5 Which has the greatest average speed?
A. a boat sailing 80 km in 2 hours
B. a car driving 90 km in 3 hours
c. a train traveling 120 km in 3 hours
D. a truck moving 50 km in 1 hour

With the application of resolution of vector, the net force is 197 N and the direction is 59 degree.

Resolution of forces can simply be solved by resolving to horizontal and vertical component.

In the given figure, we will resolve the forces into horizontal and vertical components.

Horizontal component

Fh = 80 cos 80 + 60 cos 30 + 70 cos 60

Fh = 13.89 + 51.96 + 35

Fh = 100.85 N

Vertical Component

Fv = 80 sin 80 + 60 sin 30 - 70 sin 60

Fv = 78.78 + 30 + 60.62

Fv = 169.4 N

Resultant force = √( Fh² + Fv²)

Resultant force = √(100.85² + 169.4²)

Resultant force = √(10170.7 + 28696.4)

Resultant force = √38867.06

Resultant force = 197.15 N

The direction will be

Tan Ф = Fv/Fh

Tan Ф = 169.4 / 100.85

Tan Ф = 1.68

Ф = \(tan^{-1}\)(1.68)

Ф = 59.23

Therefore, the magnitude of resultant force is 197.15 N and the direction is 59 degree north east

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According to Law of Universal Gravitation, the graph between Force and distance is hyperbolic as the force depends sqaure of the distance. Therefore, the correct option is (4).

The nature of the image formed by the convex lens is virtual, the position of the image is 30 cm away from the lens on the same side as the object, and the size of the image is twice the size of the object. The magnification is 2, meaning the image is magnified.

Given:

Object height (h) = 5 cm

Focal length of the convex lens (f) = 10 cm

Object distance (u) = 15 cm (positive since it's on the same side as the incident light)

To determine the nature, position, and size of the image, we can use the lens formula:

1/f = 1/v - 1/u

Substituting the given values:

1/10 = 1/v - 1/15

To simplify the equation, we find the common denominator:

3v - 2v = 2v/3

Simplifying further:

v = 30 cm

The image distance (v) is 30 cm. Since the image distance is positive, the image is formed on the opposite side of the lens from the object.

To find the magnification (M), we use the formula:

M = -v/u

Substituting the values:

M = -30 / 15 = -2

The magnification is -2, indicating that the image is inverted and twice the size of the object.

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Answer Explanation:

d = vt

You will be 3(15) = 45 m west of where you began.

As we do not know where the lion is to begin with, it's hard to say where we will end up relative to it.

Answer:

The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 feet) per second. That's about 186,282 miles per second — a universal constant known in equations as "c," or light speed.

\(s\frac{d}{t}\)

Explanation:

hope this helps you my friend

Answer:

The graph of the velocity of an object in free fall would look like a straight line sloping downward. As the object falls, its velocity increases at a constant rate, so the graph of its velocity versus time will be a straight line with a negative slope. This is because acceleration due to gravity is a constant -9.8 meters per second squared, so the velocity of a free-falling object will increase by 9.8 meters per second every second.

Therefore, the graph that shows the change in velocity of an object in free fall is a straight line with a negative slope. Here is an example of such a graph:

Free Fall Velocity Graph

Answer: Fitness assessments are designed to screen for risk of heart disease.

Explanation:

Fitness assessments are medical examinations that are designed to measure a person's physical fitness and identify any health risks they may have. These assessments may include tests of strength, endurance, flexibility, and cardiovascular fitness. One of the primary objectives of a fitness assessment is to screen for the risk of heart disease, which is a major health concern that can be prevented or treated through exercise and other lifestyle changes. While fitness assessments may identify specific injuries or medical conditions, their primary focus is on evaluating a person's overall health and fitness.

We have that The  moles of air are in the cylinder and the volume would this air occupy at 1.0 atm and room Temperature is

From the question we are told

Generally the equation for the Volume of Cylinder  is mathematically given as

\(V=\pi r^2l\\\\V=\pi *{\frac{20}{2*100}}*1\\\\V=31.4L\)

Therefore

The equation for the ideal gas  is mathematically given as

\(PV=nRT\\\\n=\frac{PV}{RT}\\\\n=\frac{180*31.4}{0.082*300}\\\\n=229.756\)

Generally the equation for the ideal gas  is mathematically given as

\(PV=nRTWhere\\\\V=\frac{nRT}{P}\\\\V=229.756*0.082*300\\\\V=5651.997L\)

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Explanation:

A. Stems absorb water from the soil.

B. Stems transport water and minerals.

Hope this helps you

have a good day.

Answer : Stems produce water and soil

And Stems help turn the leaves towards sunlight.

Explanation:

Because of this picture, (if its not obvious), the 2 ones that i got wrong, are not the answer, and the 2 in the middle are is the answer.

The kilogram is an SI base unit that makes up part of the unit of energy, therefore the correct answer is option D

A unit of measurement is a specified magnitude of a quantity that is established and used as a standard for measuring other quantities of the same kind. It is determined by convention or regulation.

The base SI units are meter, kilogram, second, kelvin, ampere, candela, and mole

The unit of energy is Joules which is equivalent in mks unit as Kg m²s⁻²

Thus, The kilogram is an SI base unit that makes up part of the unit of energy, therefore the correct answer is option D

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Answer:

a) 19.4 m/s

b) 19 m/s

Explanation:

a) In the given question,

the potential energy at the initial point = Ui = 0

the potential energy at the final point = Uf = mgh

the kinetic energy at the initial point = Ki = 1/2 mv₀².

the kinetic energy at the final point = Kf = 0

work done by air= Ea= fh =  0.262 N

Now, using the law of conservation of energy

initial energy= final energy

Ki +Ui = Kf + Uf +Ea

1/2 mv₀² + 0 = 0 + mgh + fh

1/2 mv₀² = mgh + fh

h = v₀²/ 2g (1 +f/w)

calculate m

m= w/g = 5.29 /9.8

= 0.54 kg

h = 20 ²/ (2 x9.80) x (1 0.265/5.29)

h = 19.4 m.

b) 1/2 mv² + 2fh = 1/2 mv₀²

Vg = 19 m/s

Answer:

Explanation:

C

Answer:

Correct Answer: B. Beaker A will be 72 °C and beaker B will be 28 °C.

This one is actually right!

Answer:

Speed of the spacecraft right before the collision: \(\displaystyle \sqrt{\frac{2\, G\cdot M_\text{e}}{R\text{e}}}\).

Assumption: the earth is exactly spherical with a uniform density.

Explanation:

This question could be solved using the conservation of energy.

The mechanical energy of this spacecraft is the sum of:

Let \(m\) denote the mass of this spacecraft. At a distance of \(R\) from the center of the earth (with mass \(M_\text{e}\)), the gravitational potential energy (\(\mathrm{GPE}\)) of this spacecraft would be:

\(\displaystyle \text{GPE} = -\frac{G \cdot M_\text{e}\cdot m}{R}\).

Initially, \(R\) (the denominator of this fraction) is infinitely large. Therefore, the initial value of \(\mathrm{GPE}\) will be infinitely close to zero.

On the other hand, the question states that the initial kinetic energy (\(\rm KE\)) of this spacecraft is also zero. Therefore, the initial mechanical energy of this spacecraft would be zero.

Right before the collision, the spacecraft would be very close to the surface of the earth. The distance \(R\) between the spacecraft and the center of the earth would be approximately equal to \(R_\text{e}\), the radius of the earth.

The \(\mathrm{GPE}\) of the spacecraft at that moment would be:

\(\displaystyle \text{GPE} = -\frac{G \cdot M_\text{e}\cdot m}{R_\text{e}}\).

Subtract this value from zero to find the loss in the \(\rm GPE\) of this spacecraft:

\(\begin{aligned}\text{GPE change} &= \text{Initial GPE} - \text{Final GPE} \\ &= 0 - \left(-\frac{G \cdot M_\text{e}\cdot m}{R_\text{e}}\right) = \frac{G \cdot M_\text{e}\cdot m}{R_\text{e}} \end{aligned}\)

Assume that gravitational pull is the only force on the spacecraft. The size of the loss in the \(\rm GPE\) of this spacecraft would be equal to the size of the gain in its \(\rm KE\).

Therefore, right before collision, the \(\rm KE\) of this spacecraft would be:

\(\begin{aligned}& \text{Initial KE} + \text{KE change} \\ &= \text{Initial KE} + (-\text{GPE change}) \\ &= 0 + \frac{G \cdot M_\text{e}\cdot m}{R_\text{e}} \\ &= \frac{G \cdot M_\text{e}\cdot m}{R_\text{e}}\end{aligned}\).

On the other hand, let \(v\) denote the speed of this spacecraft. The following equation that relates \(v\!\) and \(m\) to \(\rm KE\):

\(\displaystyle \text{KE} = \frac{1}{2}\, m \cdot v^2\).

Rearrange this equation to find an equation for \(v\):

\(\displaystyle v = \sqrt{\frac{2\, \text{KE}}{m}}\).

It is already found that right before the collision, \(\displaystyle \text{KE} = \frac{G \cdot M_\text{e}\cdot m}{R_\text{e}}\). Make use of this equation to find \(v\) at that moment:

\(\begin{aligned}v &= \sqrt{\frac{2\, \text{KE}}{m}} \\ &= \sqrt{\frac{2\, G\cdot M_\text{e} \cdot m}{R_\text{e}\cdot m}} = \sqrt{\frac{2\, G\cdot M_\text{e}}{R_\text{e}}}\end{aligned}\).

W = 25 J

Explanation:

Work done on an object is defined as

\(W = Fd = (10\:\text{N})(2.5\:\text{m}) = 25\:\text{J}\)

Answer:

920000

Explanation:

Each kg contains 1,000 grams

Answer:

The ambient temperature is 35°C.

It takes 15 minutes to cool the substance from 40°C to 35°C.

Explanation:

Using Newton's Law of Cooling to answer the given problem.

\(\boxed{\left\begin{array}{ccc}\text{\underline{Newton's Law of Cooling:}}\\\\ \frac{dT}{dt} =-k(T-T_a)\end{array}\right}\)

Given:

The time it takes to cool from 50°C to 45°C = 3 minutes

The time it takes to cool from 45°C to 40°C = 5 minutes

Find:

Time ambient temperature and the time it takes to cool the substance from 40°C to 35°C

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

(1) - Using first initial condition:

\(\text{Avg temp =} \ \frac{50+45}{2}=\boxed{47.5 \textdegree C}\\\\\Longrightarrow \frac{50-45}{3}=-k(47.5-T_a) \\\\\Longrightarrow \boxed{ \frac{5}{3}=-k(47.5-T_a)}\)

(2) - Using the second initial condition:

\(\text{Avg temp =} \ \frac{45+40}{2}=\boxed{42.5 \textdegree C}\\\\\Longrightarrow \frac{45-40}{5}=-k(42.5-T_a) \\\\\Longrightarrow \boxed{1=-k(42.5-T_a)}\)

(3) - Now we have a system of equations.

\(\left \{ \frac{5}{3}=-k(47.5-T_a)}} \atop {1=-k(42.5-T_a)}}} \right.\)

(4) - Solve the system by dividing the top equation by the bottom equation.

\(\Longrightarrow \frac{\frac{5}{3}=-k(47.5-T_a)}{1=-k(42.5-T_a)} \\\\\Longrightarrow\frac{5}{3}=\frac{47.5-T_a}{42.5-T_a}\\ \\ \Longrightarrow 5(42.5-T_a)=3(47.5-T_a)\\\\\Longrightarrow 212.5-5T_a=142.5-3T_a\\\\\Longrightarrow 2T_a=70\\\\\therefore \boxed{T_a=35 \textdegree C}\)

Thus, the ambient temperature is 35°C.

(5) - Find the value of "k" using either of the two previous equations

\(1=-k(42.5-T_a)\\\\\Longrightarrow 1=-k(42.5-35)\\\\\Longrightarrow 1=-7.5k\\\\\Longrightarrow \boxed{ k \approx -0.133}\)

(6) - Now finding "dt"

\(\text{Avg temp =} \ \frac{40+35}{2}=\boxed{37.5 \textdegree C}\\\\\Longrightarrow \frac{40-35}{dt}=0.133(37.5-35) \\\\\Longrightarrow \frac{5}{dt}=0.3325\\\\\therefore \boxed{dt \approx15 \ min}\)

Thus, it take 15 minutes to cool the substance from 40°C to 35°C.

At this precise moment, the person's speed is decreasing.

The man's friend is at a distance 552.5 m away.

Speed of sound in air, v = 340 m/s

Time after which the echo is heard, t = 3.25 s

The expression for the total distance covered by the sound in the given time,

d = v x t

d = 340 x 3.25

d = 1105 m

Therefore, the distance where the friend is staying would be half of the total distance covered by the sound during the given time.

So, the distance of the friend from the man,

d' = d/2

d' = 1105/2

d' = 552.5 m

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To solve the problem, let's break it down into three parts:

1. Determining the distance covered by cars A and B as a function of time:

For uniformly accelerated rectilinear motion, we can use the following equation to calculate the distance covered:

distance = initial velocity * time + (1/2) * acceleration * time^2

For car A:

The initial velocity is 0 m/s, and the acceleration is 4 m/s².

So, the distance covered by car A at time t is:

d¹(t) = 0.5 * 4 * t^2 = 2t^2

For car B:

The initial velocity is 0 m/s, and the acceleration is -2 m/s² (opposite direction to car A).

So, the distance covered by car B at time t is:

d²(t) = 0.5 * -2 * t^2 = -t^2

2. Deducing the time of meeting for the two cars:

To find the time of meeting, we need to set the distances covered by both cars equal to each other:

2t^2 = -t^2

Simplifying the equation:

2t^2 + t^2 = 0

3t^2 = 0

Since the equation equals zero, the only solution is t = 0. This means that the two cars meet at the starting point at t = 0.

3. Considering car B in uniform rectilinear motion with a speed of 10 m/s:

If car B is moving at a constant speed of 10 m/s, it means its acceleration is 0 m/s². Therefore, the equation for car B's distance covered becomes:

d²(t) = initial velocity * time = 10 * t = 10t

Now, we can answer the preceding questions using this new equation for car B.

1. The distance covered by car A at time t is still d¹(t) = 2t^2.

The distance covered by car B at time t is now d²(t) = 10t.

2. The time of meeting for the two cars can be found by setting the distances equal to each other:

2t^2 = 10t

Simplifying the equation:

2t^2 - 10t = 0

2t(t - 5) = 0

From this equation, we have two solutions:

t = 0 (the initial meeting point)

t = 5 seconds (when the two cars meet again after 5 seconds)

Therefore, the cars meet again after 5 seconds.

Please note that the distances calculated above are in terms of t, the time elapsed since t = 0.

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♥️ \(\large{\textcolor{red}{\underline{\mathcal{SUMIT\:\:ROY\:\:(:\:\:}}}}\)

The best inference that can be made by using the graph for the speed of the car after 3 seconds would be 17 meters / seconds , therefore the correct answer is option B.

The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object.

As given in the problem statement if you perform an experiment to measure the speed of a car over time and the results are shown in the graph,

The best inference that can be made by using the graph for the speed of the car after 3 seconds would be 17 meters/seconds, therefore the correct answer is option B.

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The magnitude of the cannonball's velocity after 1.23 s will be 59.46 m/sec.

The change of distance with respect to time is defined as speed. Speed is a scalar quantity. It is a time-based component. Its unit is m/sec.

The given data in the problem is

u is the initial velocity of canonball= 47.4 m/sec

g is the acceleration of free fall = 9.81 m/sec²

v is the velocity after 1.23 s

According to Newton's first equation of motion,

\(\rm v=u +gt \\\\ v= 47.4 \ m/sec + 9.81 \ m/sec^2 \times 1.23 sec \\\\\ v=59.46 \ m/sec\)

Hence, the magnitude of the cannonball's velocity after 1.23 s will be 59.46 m/sec.

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Answer:

Explanation:

The tank is half full so height of water level is at 1 m . Centre of gravity of water will be at height of .5 m . Pressure will act at this point .

Pressure = h d g where h is height of centre of mass of water column , d is density of water and g is acceleration due to gravity .

Pressure of water column  = .5 x 10³ x 9.8 = 4.9 k Pa .

Air is pressurized to 5 kPa so

resultant pressure  on one side of the tank due to the air and water

= 4.9 + 5 kPa = 9.9 kPa .

Total force on one face = pressure x area of one face under water

= 9.9 x 10³ x .5 x 2²

= 19.8 kN .

Answer:

Natural selection.

Explanation:

Natural selection can be defined as a biological process in which species of living organisms having certain traits that enable them to adapt to environmental factors such as predators, competition for food, climate change, sex mates, etc., tend to survive and reproduce, as well as passing on their genes to subsequent generations.

Simply stated, natural selection entails the survival of the fittest. Therefore, the species that are able to adapt to the environment will increase in number while the ones who can't adapt will die and go into extinction.

On the other hand, artificial selection is also known as selective breeding and it is a process that involves humans (breeders) selecting the animal or plant with desirable traits in order to reproduce favorable offspring having phenotypic traits.

Answer: c

Explanation:

Answer:

answer c

Explanation:

The force acting on the system of two blocks connected by a rope passing over a pulley is -13.26 N.

The system of two blocks connected by a rope passing over a pulley are M1 and M2, where M1 rests on the triangle edge to the left of the pulley, which makes an angle of theta subscript 1 with the base of the triangle. The coefficient of friction between box M1 and the surface is mu subscript 1. M2 rests on the triangle edge to the right of the pulley, which makes an angle of theta subscript 2 with the base of the triangle.

The coefficient of friction between box M2 and the surface is mu subscript 2. The system sits atop a scalene triangle whose long edge forms the base. The pulley is attached to the apex of the triangle.M1 has a mass of 2.25 kg and is on an incline of angle 1=42.5∘ that has a coefficient of kinetic friction 1=0.205. M2 has a mass of 5.55 kg and is on an incline of angle 2=33.5∘ that has a coefficient of kinetic friction 2=0.105.The free-body diagram of M1 shows that the weight of M1 acts straight downwards (vertically) and the normal force acts perpendicular to the slope.

The force of friction opposes the motion and acts opposite to the direction of motion.M1 = 2.25 kgTheta subscript 1 = 42.5 degreesMu subscript 1 = 0.205g = 9.81 m/s²In the free-body diagram of M2, the normal force acts perpendicular to the incline of the slope, the weight of the object acts vertically downwards and parallel to the incline, and the force of friction opposes the motion and acts opposite to the direction of motion.M2 = 5.55 kgTheta subscript 2 = 33.5 degreesMu subscript 2 = 0.105g = 9.81 m/s²The tension in the string is the same throughout the rope. Since the masses are being pulled by the same rope, the acceleration of the objects is the same as the acceleration of the rope.

The tension in the string is directly proportional to the acceleration of the objects and the rope.A system of two blocks connected by a rope passing over a pulley has a total mass of M. The acceleration of the system is given by the formula below:a = [(m1-m2)gsin(θ1) - μ1(m1+m2)gcos(θ1)] / (m1 + m2)Where, μ1 = 0.205 is the coefficient of friction of block M1θ1 = 42.5 degrees is the angle of the incline of block M1M1 = 2.25 kg is the mass of block M1M2 = 5.55 kg is the mass of block M2g = 9.81 m/s² is the acceleration due to gravitysinθ1 = sin 42.5 = 0.67cosθ1 = cos 42.5 = 0.75The acceleration of the system is:a = [(2.25-5.55)(9.81)(0.67) - (0.205)(2.25+5.55)(9.81)(0.75)] / (2.25 + 5.55)a = -1.7 m/s² (the negative sign indicates that the system is accelerating in the opposite direction).

The force acting on the system is given by:F = MaWhere M is the total mass of the system and a is the acceleration of the system. The total mass of the system is:M = m1 + m2M = 2.25 + 5.55M = 7.8 kgThe force acting on the system is:F = 7.8(-1.7)F = -13.26 N (the negative sign indicates that the force is acting in the opposite direction).

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The average acceleration of the motorcycle over the given distance is approximately 9.39 m/s².

To calculate the average acceleration of the motorcycle, we can use the formula:

Average acceleration = (final velocity - initial velocity) / time

First, let's convert the final velocity from km/h to m/s since the distance is given in meters. We know that 1 km/h is equal to 0.2778 m/s.

Converting the final velocity:

Final velocity = 78 km/h * 0.2778 m/s = 21.67 m/s

Since the motorcycle starts from rest (initial velocity is zero), the formula becomes:

Average acceleration = (21.67 m/s - 0 m/s) / time

To find the time taken to reach this velocity, we need to use the formula for average speed:

Average speed = total distance/time

Rearranging the formula:

time = total distance / average speed

Plugging in the values:

time = 50 m / 21.67 m/s ≈ 2.31 seconds

Now we can calculate the average acceleration:

Average acceleration = (21.67 m/s - 0 m/s) / 2.31 s ≈ 9.39 m/s²

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At the end of the Electroweak era, matter and antimatter annihilate each other. Because of a small imbalance in the ratio, the universe is left with only matter.

The baryogenesis process refers to the hypothetical mechanism or mechanisms that generated the observed baryon asymmetry in the universe which refers to the fact that there is much more matter than antimatter

If the universe were perfectly symmetric between matter and antimatter the particles and antiparticles would have annihilated each other completely leaving behind only radiation.

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High blood pressure, high LDL cholesterol, diabetes, smoking, exposure to secondhand smoke, obesity, a poor diet, and inactivity are the main risk factors for heart disease and stroke.

High blood pressure, high cholesterol, and smoking are the three main risk factors for heart disease that at least half of all Americans (47%) have. Age and family history are two uncontrollable risk factors for heart disease.

The most frequent cause of coronary artery disease is atherosclerosis, which is a buildup of fatty plaques in the arteries. Poor diet, lack of exercise, obesity, and smoking are risk factors. Choosing a healthy lifestyle can help reduce the risk of atherosclerosis.

The most prevalent type of heart disease is coronary heart disease (CHD). It happens when plaque deposits cause the arteries that carry blood to the heart to constrict or stiffen. Fat, cholesterol, and other components found in blood make up plaque. The term "atherosclerosis" also refers to this plaque accumulation.

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