mechanics (mass, force, acceleration, work, energy, momentum, velocity) - Category wise Question and Answer Practice Test with Solutions

Question : 6

A balloon filled with CO₂ released on earth would (neglect viscosity of air)

a) fall with a constant acceleration 3.4 m/s²

b) fall with an acceleration 9.8 m/s²

c) climb with an acceleration 9.8 m/s²

d) fall with acceleration and then would attain a constant velocity

Question : 7

A passenger in a moving train tosses a coin. If the coin falls behind him, the train must be moving with

a) a uniform speed

b) a deceleration

c) an acceleration

d) any of the above

Question : 8

A man waves his arms while walking. This is to

a) increase the velocity

b) ease the tension

c) keep constant velocity

d) balance the effect of earth’s gravity

Question : 9

When a stone tied to a string is whirled in a circle, the work done on it by the string is

a) zero

b) negative

c) positive

d) undefined

Question : 10

In case of negative work the angle between the force and displacement is

a) 90°

b) 45°

c) 0°

d) 180°