A body initially at rest, starts moving with a constant acceleration of 0.5 ms^-2 and travels a distance 25 m, then its final velocity is:

1. 5 ms^-1
2. 20 ms^-1
3. 15 ms^-1
4. -15 ms^-1

A car starting from rest accelerates uniformly to acquire a speed 20 km h^-1 in 30 min. The distance travelled by car in this time interval will be —

1. 600 km
2. 5 km
3. 6 km
4. 10 km

Assertion (A) : The displacement of a body can be zero even if the distance travelled by it is not zero.

Reason (R) : Displacement is the shortest distance from the initial to the final position of body.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true and R is not the correct explanation of A
3. assertion is false but reason is true
4. assertion is true but reason is false

Assertion (A) : For a given time interval, average velocity and average speed can have different values.

Reason (R) : Speed is a scalar quantity whereas velocity is a vector quantity.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true and R is not the correct explanation of A
3. assertion is false but reason is true
4. assertion is true but reason is false