A constant force acting on a body of mass 20g, produces in it a velocity of 27cm/sec in 6 seconds. If the body starts from rest, then the magnitude of the force is
80 dyne
90 dyne
95 dyne
100 dyne
The motion of rocket is an example for which law.
Newton's 1st law
Newton's 2nd law
Newton's 3rd law
Law of conservation of momentum.
When the glass vessels fall on a hard floor they break, but they do not break when the fall on a carpet or sand. Which law is used?
law of conservation of momentum
A shell of mass 0.020 kg is fired by a gun of mass 100 kg . If the muzzle speed of the shell is 80ms-1. What is the recoil speed of gun.
15 cm-1
1.6 cms-1
1.9 cms-1
2 cms-1
A bullet of mass m, is fired into a large block of wood of mass M with velocity v. The final velocity of the system is
v/(M + m)
v(M + m)/m
(mv/M)
mv/(M + m)
A helicopter of mass 1000 kg rises with a vertical acceleration of 15ms-2. The crew and the passenger weight 300 kg give the magnitude force on the floor by the crew and passenger.
10 N
zero
7.5 × 103N
8 N
A bullet of mass 0.04 kg moving with a speed of 90ms-1 enters a heavy wooden block and is stopped after a distance of 60cm. What is the average resistive force exerted by the block on the bullet?
250N
260N
270N
300N
