The upper half of an inclined plane of inclination θ is perfectly smooth while the lower is rough.A body starting from rest at the top comes back to rest at the bottom,if the coefficient of friction for the lower half is given by
μ = sin θ
μ = cotθ
μ = 2 cosθ
μ = 2 tanθ
A horse pulls the cart. Which of the following forces makes the cart move?
force exerted by the horse on the cart
force exerted by the ground on the cart
force exerted by the ground on the horse
force exerted by the horse on the ground
A rocket with a lift of mass 20,000 kg is blasted upward with an initial acceleration of 5 m/s2 .Calculate the initial thrust of the blast.
3.25 x 105 N
2.96 x 105 N
4.35 x 105 N
1.45 x 105 N
A block is lying static on the floor.The maximum value of static frictional force on the block is 10 N.If a horizontal force of 8 N is applied to the block,what will be the frictional force on the block ?
2 N
18 N
8 N
10 N
Friction is the result of
gravitational acceleration
molecular interaction
magnetic interaction
nuclear interaction
A shell is fired from a canon, it explodes in mid air, its total
momentum increases
momentum decreases
kinetic energy increases
kinetic energy decreases
Two iron blocks of equal mass but with double surface area slide down an inclined plane with friction coefficient μ.If the first block with surface area A experience a frictional force f, then the second block with surface area 2A will experience a frictional force
f/2
f
2f
4f
A smooth inclined plane has length 10 m and the angle of inclination is 300. A body of mass 2 kg is released from rest at the top of the inclined plane. What is its acceleration down the inclined plane?
10 ms-2
5√3 ms-2
5 ms-2
20/√3 ms-2
Two balls of mass 1 kg and 2 kg respectively are connected to the two ends of the spring. The two balls are pressed together and placed on a smooth table. When released the lighter ball moves with acceleration of 2 ms-2. The acceleration of the heavier ball will be
4 ms-2
2 ms-2
1 ms-2
0.5 ms-2
A balloon contains 10 g of air. The air begins to escape from a small hole in the balloon at the rate of 4 cms-1 and it completely shrinks in 2 seconds. What is the average force on the balloon?
5 dyne
10 dyne
15 dyne
20 dyne
