Two blocks P and Q are released at the top of a rough inclined plane so that P slides along the plane and Q falls down freely. Which will have higher velocity on reaching the ground?
P
Q
Both will reach the ground with same velocity
It depends on the coefficient of friction
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 body is at rest on the surface of the earth. Which of the following statement is correct?
No free is acting on the body
Only weight of the body acts on it.
Net downward force is equal to the net upward force.
None of the above statement is correct
Physical independence of force is a consequence of
third law of motion
second law of motion
first law of motion
All of the above
A light string passing over a smooth light pulley , connects two blocks of masses m1 and m2 (vertically).If the acceleration of the system is (g/8),then the ratio of masses is
8 : 1
9 : 7
4 : 3
5 : 3
When a bullet of mass 5 kg is fired, the impulse on it is 200 Ns. If the mass of the gun is 10 kg, then the recoil velocity of the gun is
20 ms-1
2 ms-1
0.2 ms-1
0.02 ms-1
If the force on a rocket moving with a velocity of 300 m/s is 345 N, then the rate of combustion of the fuel ,is
0.55 kg/s
0.75 kg/s
1.15 kg/s
2.25 kg/s
A shell is fired from a canon, it explodes in mid air, its total
momentum increases
momentum decreases
kinetic energy increases
kinetic energy decreases
A fireman wants to slide down a rope. The breaking load for the rope is 3/4th of the weight of the man. With what minimum acceleration should the fireman slide down? Acceleration due to gravity is g.
1/4 g
1/2g
3/4g
zero
A body of mass 10 kg falls vertically on a muddy ground with a velocity of 20 m/s and penetrates through a vertical depth of 0.3 m.Calculate the average force exerted by the muddy ground.Take g = 10 m/s2 .
6767 N
7894 N
7845 N
5894 N