Question

1. When you lower a book of mass m down slowly through a distance h from yourself, the work done

by you on the book is [ ]

a) mgh b) – mgh c) Zero d) > mgh

2. A block of mass 1 kg moves alogn X - axis with variable velocity  

2

v t m s  3 . The net work done

on the block from t = 1s to t = 2s [ ]

a) 10 J b) 72 J c) 4.5 J d) 67.5 J

3. A block of mass m moving initially with speed v0

enters on a rough horizontal surface. Find total

distance travelled by the block on the rough surface. Assume the coefficient of friction is  [ ]

a)

2

0

v

g

b)

2

0

2

v

g

c)

2

0

3

v

g

d)

2

0

4

v

g

4. A block of mass 1 kg is projected with initial velocity (v0

) of 10 m/s on a rough inclined surface. The

block moves up and comes back to its initial position and stops. Find work done by the friction on

the block [ ]

a) Zero

v0



b) – 50 J

c) – 100 J

d) 50 J

5. A ball of mass 10g is projected upward with an initial velocity 10 m/s and comes back and finally

achieved a velocity of 5 m/s at the piont of projection. Find the work done by air resistance. (Ne-

glect buoyancy force due to air) [ ]

a) 0.375 J b) 0.275 J c) – 0.375 J d) Zero

6. A block of mass 1 kg is connected with a fixed wall through a light spring of constat k = 100 N/m.

The surface are frictionless. Initially, spring is in relaxed position. A horizontal force F of 50 N is

applied on the block. Find the maximum elongation of the spring [ ]

a) 1 m

F = 50N

b) 0.5 m

c) 0.25 m

d) 0.1 m

7. In previous problem, find maximum speed of the block during the motion of the block [ ]

a) 1 m/s b) 2 m/s c) 5 m/s d) 10 m/s​

Answer 1

Answer:

in that pic 6 one answer is there