A person swimming in a fresh water pool obeys
Newton's second law
Gravitational law
Newton's third law
Newton's first law
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
When two surfaces are coated with lubricant,then they
stick to each other
slide upon each other
roll upon each other
none of these
A machine gun fires a bullet of mass 40 g with a velocity 1200 m/s.The man holding it can exert a maximum force of 144 N on the gun.How many bullets can he fire per second at the most ?
one
four
two
three
A car of mass m is moving with momentum p.If μ be the coefficient of friction between the tyres and the road, what will be stopping distance due to friction alone ?
p2 / 2μg
p2 / 2mμg
p2 / 2m2μg
p2 / 2mg
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
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
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
Friction is the result of
gravitational acceleration
molecular interaction
magnetic interaction
nuclear interaction
A force of 100 N need to be applied parallel to a smooth inclined plane just to hold a body on it. The angle of inclination of the inclined plane is 300. How much horizontal force need to be applied to do the same?
50 N
87 N
100 N
115 N
