50 g ball collides elastically with a 150 g ball. The initial velocity of the first ball is 8 ms^-1 to the left while the second ball is at rest. The velocity of first ball after collision is ______________.
(a) -3 ms^-1
(b) -4 ms ^-1
(c) -5 ^ms-1
(d) -6 ms ^-1
A 50 g ball collides elastically with a 150 g ball. The initial velocity of the first ball is 8 ms’ to the right while the second ball is at rest. The velocity of second ball after collision is ________________.
(a) 3 m-s^-1
(b) 4 m-s^-1
(c) 5 m-s^-1
(d) 6 m-s^-1
A 100 g plastic ball is moving to right with a velocity of 20 ms’.It makes a head on collision with a 8 kg steel balls, initially at rest. The velocity of plastic ball after collision is
(a) -16.5 ms1
(b)-19.5 ms
(c)-26.5 ms
(d)-31.5 ms
A 100 g plastic ball is moving to right with a velocity of 20 ms’.It makes a head on collision with an 8kg steel ball, initially at rest. The velocity of steel ball after collision is
(a) 0 ms ^-1
(b) 0.5 ms ^-1
(c) 1.5 ms ^-1
(d) 2.0 ms ^-1
The water flows out from a pipe at 3 Kgs^-1 and its velocity changes from 5 ms” to zero on striking the wall. The force on water is
(a) 10N
(b) 15N
(c) 20N
(d) 25N
A hose pipe ejects water at a sped of 0.3 ms^-1 through a hole of area 0.005m.If the water strikes a wall normally and then stops. What is the force on the wall?
(a) 0.35 N
(b) 0.45 N
(c) 0.55 N
(d) 0.65 N
A 50 g bullet is fired from a 3 kg rifle. The bullet moves with a velocity of 5 ms^-1. At what velocity, the rifle will recoil?
(a) 0.05 ms ^-1
(b) 0.06 ms ^-1
(c) 0.07 ms ^-1
(d) 0.08 ms ^-1
The momentum gained by rocket is equal to _________________________________________________.
(a) Momentum of the gas expelled from the engine
(b) Momentum of the space around the rocket
(c) Both of them
(d) None of these
In order to provide enough upward thrust to over come gravity, a typical rocket consumes fuel about _________.
(a) 10 kgs’^-1
(b)100 kgs^-1
(c) 1000 kgs^-1
(d)10000 kgs^-1
In order to provide enough upward thrust to overcome gravity, a typical rocket ejects the burnt gases at speeds of over ______________.
(a) 40 ms^-1
(b) 400 ms^-1
(c) 4000 ms^-1
(d) 40000 ms^-1
How much of the lauδnch mass of a rocket consists of fuel only?
(a) 10 %
(b) 30%
(c) 50 %
(d) 80 %
A rocket consumes 10000 kgs^-1 of fuel and ejects the burnt gases at a sped of 4900 ms^-1. What will be the thrust produced by the engine on the body of the rocket?
(a) 5.6 MN
(b) 4.9 MN
(c) 4.2 MN
(d) 3.5 MN
When the fuel in the rocket is burnt and ejected then __________________.
(a) The mass of the rocket decreases
(b)The acceleration of the rocket increases
(c) Both of them
(d) None of these
A ball is thrown from a point 5 m above the ground. What horizontal distance does the ball cover in 10 s if the horizontal velocity has the magnitude of 1O ms^1 ?
(a) 100 m
(b) 200 m
(c) 300 m
(d) 400 m
A stone is fallen from the edge of the building so that it reaches the ground in 12 s. What vertical distance does the stone cover?
(a) 4140 m
(b) 3600 m
(c) 706 m
(d) 189 m