- State two differences between scalar and vector quantities.
- State two differences between distance and displacement.
- State two differences between speed and velocity.
- A car moving along a circular path of radius 140 m, completes one round in 20 s. What is the speed of the car (ii) the displacement of the car?
- Give an example of a body moving with a uniform speed and uniform acceleration. Justify your answer.
- (a) What do you understand by the term : (i) Distance (ii) Displacement? (b) State the SI units of distance and displacement.
- A body is moving along a circular path of radius R. What will be the distance covered and the displacement of the body after half revolution?
- A person starts from his house and travels a circular distance of 15 km around the walled city before returning back. What is (a) the distance covered by the person, (b) the displacement of the person
- Define the terms : (i) speed and (ii) velocity.
- Why is speed considered an incomplete physical quantity? Name a quantity akin to speed which describes the motion of a particle more accurately.
- Name a physical quantity which corresponds to: (a) rate of change of displacement (b) rate of change of velocity
- Arrange the following speeds in the increasing order : (i) A scooter moving with a speed of 300 m per minute. (ii) A car moving with a speed of 27 km per hour.
- Draw a diagram to show the motion of a body whose speed remains constant, but the velocity changes continuously.
- Draw a velocity versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.
- A bus travels at a distance of 120 km with a speed of 40 km/h and returns with a speed of 30 km/h. Calculate the average speed for the entire journey
- A bus accelerates uniformly from 54 km/h to 72 km/h in 10 s. Calculate : (i) the acceleration (ii) the distance covered by the bus in that time
- (a) An object travels 16 m in 4 seconds and the next 16 m in 2 seconds. Calculate the average speed of the object. (b) Give an example of an object moving under uniform circular motion.
- The driver of a train A travelling at a speed of 54 km/h applies brakes and retards the train uniformly. The train stops in 5 s. Another train B is travelling on the parallel track with a speed of 36 km/h. This driver also applies the brakes and the train retards uniformly. The train B stops in 10 s. Plot speed - time graph for both the trains on the same paper. Also calculate the distance travelled by each train after the brakes were applied.
- (a) A car accelerates uniformly from 18 kmh–1 to 36 kmh–1 in 5 s. Calculate : (i) acceleration (ii) distance covered by the car in that time (b) The length of minute hand of a clock is 14 cm. Calculate the speed with which the tip of the minute hand moves
- A car is moving on a straight road with a uniform acceleration. The following table gives the speed of the car at various instants of time.
Time (s) 0 10 20 30 40
50
Speed (ms–1) 5 10 15
20 25 30
21 Draw the distance-time
graph for the following situations :
(a) When a body is stationary.
(b) When a body is moving with a uniform speed.
(c) When a body is moving with variable speed and uniform
acceleration.
22 The displacement of a
moving object in a given interval of time is zero. Would the distance travelled
by the object also be zero? Justify your answer.
23 A car starts from rest
and moves along the x-axis with a constant acceleration of 5 m s–2 for 8 seconds. If it then
continues to move with a constant velocity, what distance will the car cover in
12 seconds since it started from rest?
24 A motorcyclist drives
from A to B with a uniform speed of 30 km h–1 and returns back with a
speed of 20 km h–1. Find its average speed.
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