Motion in a Straight Line · Question 25

A particle covers half of its total distance with speed v1 and the rest half distance with speed v2. Its average speed during the complete journey is

1. v1+v22
2. v1v2v1+v2
3. 2v1v2v1+v2
4. v12v22v12+v22

A boy standing at the top of a tower of 20 m height drops a stone. Assuming g = 10 m s-2, the velocity with which it hits the ground is

1. 10.0 m/s
2. 20.0 m/s
3. 40.0 m/s
4. 5.0 m/s

A particle moves a distance x in time t according to equation x = (t + 5)-1. The acceleration of particle is proportional to

1. (velocity)3/2
2. (distance)2
3. (distance)-2
4. (velocity)2/3

A ball is dropped from a high rise platform at t = 0 starting from rest. After 6 seconds another ball is thrown downwards from the same platform with a speed v. The two balls meet at t = 18 s. What is the value of v? (Take g = 10 m/s2)

1. 75 m/s
2. 55 m/s
3. 40 m/s
4. 60 m/s

A particle starts its motion from rest under the action of a constant force. If the distance covered in first 10 seconds is S1 and that covered in the first 20 seconds is S2, then

1. S2 = 3S1
2. S2 = 4S1
3. S2 = S1
4. S2 = 2S1

A bus is moving with a speed of 10 m s-1 on a straight road. A scooterist wishes to overtake the bus in 100 s. If the bus is at a distance of 1 km from the scooterist, with what speed should the scooterist chase the bus?

1. 40 m s-1
2. 25 m s-1
3. 10 m s-1
4. 20 m s-1

A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 m s-1 to 20 m s-1 while passing through a distance 135 m in t second. The value of t is

1. 12
2. 9
3. 10
4. 1.8

The distance travelled by a particle starting from rest and moving with an acceleration 43 m s-2, in the third second is

1. 103 m
2. 193 m
3. 6 m
4. 4 m

A particle shows distance - time curve as given in this figure. The maximum instantaneous velocity of the particle is around the point [figure]

1. D
2. A
3. B
4. C

A particle moving along x-axis has acceleration f, at time t, given by f = f0 (1 - tT ), where f0 and T are constants. The particle at t = 0 has zero velocity. In the time interval between t = 0 and the instant when f = 0, the particle's velocity (vx) is

1. 12f0T2
2. f0T2
3. 12f0T
4. f0T