Choose the correct answer

Laws of Motion - Science

I. Choose the correct answer

1) Inertia of a body depends on

a)              weight of the object

b)             acceleration due to gravity of the planet

c)              mass of the object

d)             Both a & b

2) Impulse is equals to

a)              rate of change of momentum

b)             rate of force and time

c)              change of momentum

d)             rate of change of mass

3) Newton’s III law is applicable

a)              for a body is at rest

b)             for a body in motion

c)              both a & b

d)             only for bodies with equal masses

4) Plotting a graph for momentum on the X-axis and time on Y-axis. slope of momen-tum-time graph gives

a) Impulsive force

b) Acceleration

c) Force

d) Rate of force

5) In which of the following sport the turning of effect of force used

a) swimming

b) tennis

c) cycling

d) hockey

6) The unit of ‘g’ is m s-2. It can be also expressed as

a) cm s-1

b) N kg-1

c) N m2 kg-1

d) cm2 s-2

7) One kilogram force equals to

a) 9.8 dyne

b) 9.8 × 104 N

c) 98 × 104 dyne

d) 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

a) 4 M

b) 2M

c) M/4

d) 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

a) decrease by 50%

b) increase by 50%

 decrease by 25%

d) increase by 300%

10) To project the rockets which of the follow-ing principle(s) is /(are) required?

a)              Newton’s third law of motion

b)             Newton’s law of gravitation

c)              law of conservation of linear momentum

d)             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