K R Prajwal

Topics: Velocity, Acceleration, Kinematics Pages: 17 (3297 words) Published: March 19, 2013
Q.1 A particle is moving in a straight line with initial velocity u and retardation αv, where v is the velocity at any time t

[a] the particle will cover a total distance u/α

[b] the particle will come to rest after 1/α

[c] the particle will continue to move for a very long time

[d] the velocity of the particle will become u/2 after time 1/α

Q.2 A particle moves along the xaxis as x = u(t-1)2 + a(t-3)3

[a] initial velocity of the particle is u

[b] the acceleration of the particle is a

[c] the acceleration of the particle is 2a

[d] the particle is at the origin at time t=3 seconds

Q.3 A particle is projected vertically upwards

[a] the speed decreases uniformly with distance

[b] the speed decreases uniformly with time

[c] the KE decrease uniformly with time

[d] KE decreases uniformly with distance

Q.4 If an observer moves at constant speed along the line joining two stationary objects> he will the two objects

[a] have the same velocity

[b] have the same speed

[c] move in opposite directions

[d] move in the same direction.

Q.5 A particle is moving with uniform acceleration along a straight line AB. Its speed at A and B are 2m/s and 14m/s respectively. Then

[a] its speed at the midpoint is 10m/s

[b] its speed at point P such that AP:PB is 1:5 is 4m/s

[c] the time to go from A to mid point of AB is double to move from mid point to B

[d] none of the above.

Q.6 A body starting from rest is moving with uniform acceleration of 5m/s2 for time 10s, and after that with uniform acceleration of 10m/s2 for 15s, then

[a] average acceleration of the body is 7.5m/s2

[b] the average acceleration is 8m/s2

[c] total distance covered is 1875m

[d] total distance covered is 2125m

Q.7 A particle moves first 10m in 2s and 20m in the next 3s and 30m in next 10s. which of the following statements are true for motion?

[a] the particle is moving with uniform velocity

[b] the average speed of the particle is 4m/s

[c] the particle is uniformly accelerated

[d] the particle has deceleration during the motion

Q.8 Suppose a and v denoted the acceleration and velocity vector if the body in one dimensional motion:

[a] speed must increase if a > 0

[b] speed must increase if v and a >0

[c] speed must decrease if a<0

[d] speed will decrease if v<0 and a>0

Q.9 The motion of the particle falling in the restive medium is given by dv/dt = A-Bv where A and B are constants. Then

[a] the initial acceleration of the body is A

[b] the velocity at which the acceleration becomes zero is A/B

[c] the velocity at any time t is A(1-e-Bt)/B

[d] all the above are wrong

Q.10 The displacement of the particle depends upon time as x = αt2 – βt3

[a] the particle will come to rest after time t=2α/3β

[b] the particle will return to the starting point after time α/β

[c] no net force acts on the particle at t=α/3β

[d] the initial velocity of the particle was zero but initial acceleration was not zero.

Q.11 A lead ball is dropped into a lake from a diving board 5m above the water. If it hits the water with certain velocity and sinks to the bottom with same constant velocity. It reaches the bottom 5s after it is dropped.

[a] the depth of the lake is 40m

[b] the depth of the lake is 50m

[c] the average velocity of the ball is 5m/s

[d] the average velocity of the ball is 9m/s

Q.12 A balloon starts rising from the ground with an acceleration of 2.5m/s2. after 4 seconds the stone is relased from the balloon. If g=10m/s2. The stone will

[a]...