Laws of Motion | Science
I. Choose the correct answer
1) Inertia of a body depends on
weight of the object
acceleration due to gravity of the planet
mass of the object
Both a & b
2) Impulse is equals to
rate of change of momentum
rate of force and time
change of momentum
rate of change of mass
3) Newton’s III law is applicable
for a body is at rest
for a body in motion
both a & b
only for bodies with equal masses
4) Plotting a graph for momentum on the X-axis and time on Y-axis. slope of momentum-time graph gives
Impulsive force
Acceleration
Force
Rate of force
5) In which of the following sport the turning of effect of force used
swimming
tennis
cycling
hockey
6) The unit of ‘g’ is m s-2. It can be also expressed as
cm s-1
N kg-1
N m2 kg-1
cm2 s-2
7) One kilogram force equals to
9.8 dyne
9.8 × 104 N
98 × 104 dyne
980 dyne
8) The mass of a body is measured on planet Earth as M kg. When it is taken to a planet of radius half that of the Earth then its value will be____kg
4 M
2M
M/4
M
9) If the Earth shrinks to 50% of its real radius its mass remaining the same, the weight of a body on the Earth will
decrease by 50%
increase by 50%
decrease by 25%
increase by 300%
10) To project the rockets which of the following principle(s) is /(are) required?
Newton’s third law of motion
Newton’s law of gravitation
law of conservation of linear momentum
both a and c
II. Fill in the blanks
1. To produce a displacement force is required.
2. Passengers lean forward when sudden brake is applied in a moving vehicle. This can be explained by inertia of motion.
3. By convention, the clockwise moments are taken as negative and the anticlockwise moments are taken as positive.
4. Gear is used to change the speed of car.
5. A man of mass 100 kg has a weight of 980 N at the surface of the Earth.