Motion Worksheet-6

Motion Worksheet-6

The numerical ratio of displacement to distance for a moving object is :

A. always less than 1 B. equal to 1 or more than 1

C. always more than 1 D. equal to 1 or less than 1

A boy is sitting on a merry-go-round which is moving with a constant speed of 10 m S^–1. This means that the boy is :

A. at rest

B. moving with no acceleration

C. in accelerated motion

D. moving with uniform velocity

In which of the following cases of motion, the distance moved and the magnitude of displacement are equal ?

A. if the car is moving on straight road

B. if the car is moving on circular road

C. if the pendulum is moving to and fro

D. if a planet is moving around the sun

The speed of a moving object is determined to be 0.06 m/s. this speed is equal to :

A. 2.16 km/h B. 1.08 km/h

C. 0.216 km/h D. 0.0216 km/h

A freely falling object travels 4.9 m in 1st second, 14.7 m in 2nd second 24.5 m in 3rd second, and so on. This data shows that the motion of a freely falling object is a case of :

A. uniform motion B. uniform acceleration

C. no acceleration D. Uniform velocity

When a car runs on a circular track with a uniform speed, its velocity is said be changing. This is because :

A. the car has a inform acceleration

B. The direction of car varies continuously

C. the car travels unequal distances un equal time intervals

D. the car travels equal distances in unequal time intervals

Which of the following statement is correct regarding velocity and speed of a moving body ?

A. velocity of a moving body is always higher than its speed

B. speed of a moving body is always higher than its velocity

C. Speed of a moving body is its velocity in a given direction

D. Velocity of a moving body is its speed in a given direction

Which of the following can sometimes be ‘zero’ for a moving body ?

(i) average velocity (ii) distance travelled (iii) average speed (iv) displacement

A. only (i) B. (i) and (ii)

C. (i) and (iv) D. only (iv)

When a car driver travelling at a speed of 10 m/s applies brakes and brings the car to rest in 20 s, then retardation will be :

A. +2 m/s² B. –2 m/s² C. –0.5 m/s² D. +0.5 m/s²

Which of the following could not be a unit of speed ?

A. km/h B. s/m C. m/s D. m s^–1

Answer:

Explanation: If the person is moving in one direction along a straight line the distance travelled and displacement will be same. Distance and displacement will be same if person is travelling from A to B

But if the person is moving from C to D the distance travelled will be more than displacement. Distance travelled is the length of curved line from C to D and displacement is the straight distance between C to D. So the ratio wil be either 1 or less than 1.

Explanation: When a body walks across a straigh line distance travelled and magnitude of displacement will be same. In case of to and fro movement of pendulam displacement will be zero since the distance between the initial positiona dn final position is zero. In other cases distance will be more than displacement.

Explanation: 0.06 m/s

1 km = 1000 m and 1 hour = 60 × 60 seconds

So speed will be 0.06 × 60 × 60/1000 kmph

Explanation: Velocity is a vector quantity and it depends upon the direction of the movement of the body.

Explanation: For example, if the body is moving in a circular path then after one complete round the difference between initial point and final point will be zero hence displacement will be zero and when displacement is zero velocity will also be zero as velocity is displacement/time

Explanation: a = (V – u)/t here ‘v’ is the final velocity, ‘u’ is the initial velocity and ‘t’ is the time taken,

by puttiong the value a = ( 0 – 10)/20 = - 0.5 (negative sign shows retardation) But in the question we are asked retardation only that means it will be 0.5 m/s²