Practice Paper
Subject Physics (2020)
Ch- 8 MOTION
CLASS IX
I. Very Short answer type questions:
- What are the uses of the distance-time graph?
- Give an example in which distance is equal to the magnitude of displacement.
- The orbit of a satellite at distance 42260 km from the earth is circular. It completes one revolution around the earth in 24 hr. Calculate its linear speed.
- Is speed a scalar or a vector quantity?
- Is displacement a vector quantity or scalar quantity?
- If the displacement of a body is zero is it necessary that the distance covered by it is also zero?
- When do the distance and displacement of a moving object have the same magnitude?
- What are the characteristics of the distance-time graph for an object moving at a uniform speed?
- What do you mean by displacement?
- Is displacement a scalar quantity?
- When do the displacement and distance of a moving body have the same value?
- What is the S.I unit of speed?
- What does the speedometer measure?
- What does the area under the velocity-time graph give?
- A bus takes 8 hours to cover a distance of 320 kilometers. What is the average speed of the bus?
- What is the slope of the body when it moves with uniform velocity?
- What does the slope of a position-time graph give?
- What does the slope of a velocity-time graph give?
- When a moving body comes to rest, then what its acceleration is: positive/ negative / zero?
- What does the odometer of an automobile measure?
II. Short Answer Type Questions:
- Are rest and motion relative terms?
- Plot the velocity-time graph showing +a and –a. How is the distance calculated from the velocity-time graph?
- Write the differences between speed and velocity.
- Why circular motion is accelerated motion? Write an expression of circular motion.
- What is meant by uniform circular motion? Give its two examples.
- Calculate the acceleration of a body that starts from rest and travels 87.5m in 5 sec.
- A car traveling at 36 km/hr speed up to 72 km/hr in 5 sec. What is the acceleration? If the same car stops in 20 sec, what is the retardation?
- A car moves 100 m due east and then 25 meters due west.
(i) What is the distance covered by the car?
(ii) What is its displacement? - A person walks along the side of a square field. Each side is 100m long. What is the maximum magnitude of displacement of the person if any time interval?
- The maximum speed of a train is 80 km/h. It takes 10 hours to cover a distance of 400 kilometers. Find the ratio of its maximum speed to its average speed.
- Given below are few speed time graphs for the motion of objects moving along a straight line which of these graphs represent the motion of the body whose speed is :(i) Increasing with time,(ii) Uniform and (iii) nonuniform.
- Define scalar and vector quantity?
- A body is moving along a circular path of radius R. What are the values of distance and displacement in the half revolution
- What is the displacement of a satellite when it makes a complete round trip along a circular path? Explain with reasoning?
- Can the displacement be greater than the distance traveled by an object?
- What is negative acceleration?
- A particle moving with a uniform velocity. What is its acceleration?
- Is it possible for a body to have zero velocity but constant acceleration? Justify your answer.
- Study the given graph and answer the following questions?
(a) Which part of the graph shows accelerated motion?
(b) Which part of the graph shows retarded motion?
(c) Calculate the distance traveled by the body in the first 4 sec of the journey graphically?
- The velocity-time graph of an object is shown in the fig:
(a) State the kind of motion that object has, from A to B and B to C.
(b) Identify the part of the graph where the object has zero acceleration.
Give reasons for your answer.
(c) Identify the part of the graph where the object has negative acceleration. Give reasons for your answer.
- The distance moved by a student at different intervals of time, while walking to school, is given in the table below:
Draw the distance-time graph for the motion of the student indicating the scale chosen. What does the shape of the graph suggest about the type of motion?Time for starting point(s) 0 10 20 30 40 50 Distance moved(m) 0 15 30 45 60 75 - Study the table:
(a) Is the car moving with constant speed?
(b) What is the average speed?
(c) Which duration represents the maximum velocity? Time 10:30am 11:00 am 11:30 am 12:00 noon 12:30 pm Distance from origin point.(km) 0 15 28 40 60 - From displacement time graph shown in fig, find (a) Velocity of A.(b) The velocity of B.
- The bus decreases its speed from 80 km/hr to 60 km/hr in 5 sec. Find the acceleration of the bus?
III. Long Answer type questions:
- 1. Differentiate between:
(a) Distance and displacement.
(b) Speed and velocity.
(c) Scalar and vectors.
(d) Uniform and non-uniform motion. - Answer the following questions:
(i) State the type of motion shown by a freely falling stone.
(ii) When a stone is thrown vertically upwards its velocity is continuously decreased. Why?
(iii) Give an example of a motion in which average velocity is zero, but the average speed is not zero. - The velocity-time graph shown below represents the motion of a body:
(a) During which interval of time, the body is moving with maximum acceleration?
(b) Calculate the average velocity for the entire journey.
- A cyclist traveled 3/4 of a circular track from A to B as shown in fig. The radius of the circular track is 400 m.
(a) What is the distance traveled by the cyclist?
(b) What is the displacement?
- The velocity-time graph shows the motion of a cyclist. Find(i) Its acceleration(ii) Its velocity after 20 s and(iii)The distance covered by the cyclist in 15 sec. Give reasons for your answer.
- Derive mathematically the first equation of motion:(i) V = u + at?
(ii) S= Ut + 1/2 at2
(iii) v2 - u2 = 2as. - Study the speed-time graph of a car alongside and answer the following:(a) What type of motion represented by AB?(b) Find acceleration from C to D.(c) Calculate the distance covered by the body from B to C. Give reasons for your answer. Scale of graph (v) : 1 cm = 20 m/s on Y-axis1 cm = 2 sec on X-axis
- A motorboat starting from rest on a lake acceleration in a straight line at a constant rate of 3.0 m/s2 for 8.0 sec. How far does the boat travel during this time?
- A train leaves New Delhi railway station at 09:00 AM and reaches Jaipur, which is at a distance of 260 km at 12:45 PM. The train reaches Alwar (at distance 150 km from New Delhi) at 11:30 AM and stops there for 15 minutes.
(i) What is the reference point for the motion of the train?
(ii) What is the average speed to the train between Alwar and Jaipur? - A scooter starts from rest, moves in a straight line with a constant acceleration and covers a distance of 64m in 4 sec.
(a) Calculate its acceleration and its final velocity.
(b) In how much time the scooter will cover half the total distance? - A body covers one complete around a circular park of circumference 176 m in 4 min. Find the displacement of the body after 6 min.
- (a)When will you say a body is in
(i) Uniform acceleration
(ii) Non-uniform acceleration.
(b) A train starts from rest and accelerates uniformly for 30 s to acquire a velocity of 108 km/h. It travels with this velocity for 20 min. The driver now applies breaks and the train retards uniformly to stop after 20 s. Find the total distance covered by the train. - Define:
(a) Displacement (b) Speed. (c) Uniform speed and non-uniform speed (d) Average speed (e) Velocity (f) Uniform velocity (g)Average velocity (h) Instantaneous velocity (i) Acceleration (j) Uniform acceleration and nonuniform acceleration (k) Retardation (deceleration)
- An object has moved through a distance. Can it have zero displacements? If yes, support your answer with an example.
- A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds?
- Which of the following is true for displacement? (a) It cannot be zero. (b) Its magnitude is greater than the distance traveled by the object.
- Distinguish between speed and velocity.
- Under what condition(s) is the magnitude of the average velocity of an object equal to its average speed?
- What does the odometer of an automobile measure?
- What does the path of an object look like when it is in uniform motion?
- During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3 × 108m s–1.
- When will you say a body is in(i) uniform acceleration? (ii) non-uniform acceleration?
- A bus decreases its speed from 80 km h–1 to 60 km h–1 in 5 s. Find the acceleration of the bus.
- A train starting from a railway station and moving with uniform acceleration attains a speed of 40km h–1 in 10 minutes. Find its acceleration.
- What is the nature of the distance-time graphs for uniform and non-uniform motion of an object?
- What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?
- What can you say about the motion of an object if its speed-time graph is a straight line parallel to the time axis?
- What is the quantity which is measured by the area occupied below the velocity-time graph?
- A bus starting from rest moves with a uniform acceleration of 0.1 m s-2 for 2 minutes. Find (a)the speed acquired, (b) the distance traveled.
- A train is traveling at a speed of 90 km h–1. Brakes are applied so as to produce a uniform acceleration of – 0.5 m s-2. Find how far the train will go before it is brought to rest.
- A trolley, while going down an inclined plane, has an acceleration of 2 cm s-2. What will be its velocity 3 s after the start?
- A racing car has a uniform acceleration of 4 m s-2. What distance will it cover in 10 s after start?
- A stone is thrown in a vertically upward direction with a velocity of 5 m s-1. If the acceleration of the stone during its motion is 10 m s–2 in the downward direction, what will be the height attained by the stone and how much time will it take to reach there?
- An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?
- Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging (a) from A to B and (b) from A to C?
- Abdul, while driving to school, computes the average speed for his trip to be 20 km h–1. On his return trip along the same route, there is less traffic and the average speed is 40 km h–1. What is the average speed for Abdul’s trip?
- A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 m s–2 for 8.0 s. How far does the boat travel during this time?
- A driver of a car traveling at 52 km h–1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h–1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars traveled farther after the brakes were applied?
- A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10 m s-2, with what velocity will it strike the ground? After what time will it strike the ground
- State which of the following situations are possible and give an example for each of these:
(a) an object with a constant acceleration but with zero velocity (b) an object moving in a certain direction with an acceleration in the perpendicular direction. - An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth.
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