then the angle between A and B isπ

• π

• π/3

• π/2

• π/4

A.

π

A 2 kg block slides on a horizontal floor with a speed of 4 m/s. It strikes a uncompressed spring, and compresses it till the block is motionless. The kinetic friction force is 15 N and spring constant is 10,000. N/m. The spring compresses by

• 5.5 cmYes

• 2.5 cm

• 11 cm

• 3.5 cm

A body is at rest at x = 0. At t = 0, it starts moving in the positive x-direction with a constant acceleration. At the same instant another body passes through x = 0 moving in the positive x-directionn with a constant speed. The position of the first body is given by x1(t) after time ‘t’ and that of the second body by x2(t) after the same time interval. Which of the following graphs correctly describes (x₁ – x₂)as a function of time ‘t’?

• 
• 
• 
• 

B.

A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time?

• 
• 
• 
• 

A.

Velocity at any time t is given by

v = u + at

v = v0 + (–g)t
v = v0 – gt

Straight line negative slope.

A body of mass m = 10^–2 kg is moving in a medium and experiences a frictional force F = –kv². Its initial speed is v₀ = 10 ms^–1. If, after 10 s, its energy is 1/8 mv₀²,the value of k will be

• 10^-4 kg m^-1

• 10^–1 kg m^–1 s^–1

• 10^-3 kg m^-1

• 10^-3 kg s^-1

A.

10^-4 kg m^-1