Q.1. A ball is thrown vertically downward with a velocity of 20m/s from the top of a tower. It hits the ground after some time with a velocity of 80m/s. The height of the tower is : (g = 10m/s2) 
A: 320 m
B: 300 m
C: 360 m
D: 340 m
v2 – u2 = 2as
(80)2 – (–20)2 = 2(–10) × s
6400 – 400 = 2 × (–10) × s
s = – 300 m
Height of tower h = 300 m
Q.2. Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t1. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be 
C: t1 – t2
As we learnt in
Case of Relative velocity -
When A & B are moving along with straight line in opposite direction.
Relative velocity of A with respect to B is.
Q.3. A particle moves so that its position vector is given by r = cosωtx + sinωty. Where ω is a constant. Which of the following is true?
A: Velocity is perpendicular to r and acceleration is directed away from the origin.
B: Velocity and acceleration both are perpendicular to r
C: Velocity is acceleration both are parallel to r
D: Velocity is perpendicular to r and acceleration is directed towards the origin. 
Q.4. If the velocity of a particle is , where A and B are constants, then the distance travelled by it between 1s and 2s is 
A: A/2 + B/3
B: 3A/2 + B
C: 3A + 7B
D: 3A/2 + 7B/3
Q.5. A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to v(x) = βx-2n, where β and n are constants and x is the position of the particle. The acceleration of the particle as a function of x, is given by : 
A: -2nβ2 e-4n + 1
B: -2nβ2 x-2n - 1
C: -2nβ2 x-4n - 1
D: -2nβ2 x-2n + 1