Work Done: Spring

Q.

If the potential energy of a spring is V on stretching it by 2 cm, then its potential energy when it is stretched by 10 cm will be

1. V/25

2. 5V

3. V/5

4. 25V

Q.

When a spring is stretched by 2 cm, it stores 100 J of energy. If it is stretched further by 2 cm, the stored energy will be increased by

1. 100 J

2. 200 J

3. 400 J

4. 300 J

Q.

A spring of spring constant $5x{10}^{3}N{m}^{-1}$ is stretched initially by $5cm$ from the unstretched position. Then the work required to stretch it further by another $5cm$is

1. $12.50N–m$

2. $18.75N–m$

3. $25N–m$

4. $6.25N–m$

Q.

When a 1.0 kg mass hangs attached to a spring of length 50 cm, the spring stretches by 2 cm. The mass is pulled down until the length of the spring becomes 60 cm. What is the amount of elastic energy stored in the spring in this condition, if g = $10m/s^2$

1. 1.5 Joule

2. 3.0 Joule

3. 2.5 Joule

4. 2.0 Joule

Q.

A spring of force constant 10 N/m has an initial stretch 0.20 m. In changing the stretch to 0.25 m, the increase in potential energy is about

1. 0.1 joule

2. 0.2 joule

3. 0.3 joule

4. 0.5 joule

Q. The potential energy function for a particle executing linear simple harmonic motion is given by V(x) = kx²/2, where k is the force constant of the oscillator. For k = 0.5 N m¯¹, the graph of V(x) versus x is shown in Fig. 6.12. Show that a particle of total energy 1 J moving under this potential must ‘turn back’ when it reaches x = ± 2 m.

Q.

A 20 - kg block attached to a spring of spring constant 5 N $m^{-1}$ is released from rest at A. The spring at this instant is having an elongation of 1 m. The block is allowed to move in smooth horizontal slot with the help of a constant force 50 N in the rope as shown. The velocity of the block as it reaches B is (assume the rope to be light)

1. 4 ms^-1

2. 2 ms^-1

3. 1 ms^-1

4. 3 ms^-1

Q.

Two springs of spring constants 1500 N/m and 3000 N/m respectively are stretched with the same force. They will have potential energy in the ratio

1. 1:4

2. 2:1

3. 1:2

4. 4:1

Q. A girl is carrying a school bag of 3kg mass on her back and moves 200m on a levelled road.The work done against the gravitational force will be (g=10 m/s^2).

Q. 44. Two identical thin rings each of radius R are co-axially placed at a distance R. If the ring have a uniform mass distribution and have masses m1 and m2 respectively, then what is the work done in moving a mass m from the centre of one ring to that of other? Is it path dependent or not?

Q.

In one of the exercises to strengthen the wrist and fingers, a person squeezes and releases a soft rubber ball. Is the work done on the ball positive, negative or zero (i) during compression (ii) During expansion?

1. While compressing; W_F = positive; while expanding, W_F = positive

2. While compressing; W_F = Negative; while expanding, W_F = Negative

3. While compressing; W_F = positive; while expanding, W_F = Negative

4. While compressing; W_F = Negative; while expanding, W_F = positive

Q.

A 20 - kg block attached to a spring of spring constant 5 N $m^{-1}$ is released from rest at A. The spring at this instant is having an elongation of 1 m. The block is allowed to move in smooth horizontal slot with the help of a constant force 50 N in the rope as shown. The velocity of the block as it reaches B is (assume the rope to be light)

1. $4m{s}^{-1}$

2. $2m{s}^{-1}$

3. $1m{s}^{-1}$

4. $3m{s}^{-1}$

Q. A car weighing 1400 kg is moving at a speed of 54km/hr up a hill when the motor stops. If it is just able to reach the destination which is at a height of 10m above the point, calculate the work done against friction

Q. A 15 gm ball is shot from a spring gun whose spring has a force constant of 600 N/m. The spring is compressed by 5 cm. The greatest possible horizontal range of the ball for this compression is $(g=10m/s^2)$

1. 6.0 m
2. 12.0 m
3. 10.0 m
4. 8.0 m

Q.

The potential energy of a certain spring when stretched through a distance 'S' is 10 joule. The amount of work (in joule) that must be done on this spring to stretch it through an additional distance 'S' will be

1. 30

2. 40

3. 10

4. 20

Q. work energy threorm

Q. FIND THE WORK DONE BY CONSERVATIVE FORCE WHEN PARTICLE MOVES FROM A(d, d)&B(2d, 2d).u=ax^2+b

Q.

what is work done by earth in completing half the rotation around the sun ?

Q.

When a 1.0 kg mass hangs attached to a spring of length 50 cm, the spring stretches by 2 cm. The mass is pulled down until the length of the spring becomes 60 cm. What is the amount of elastic energy stored in the spring in this condition, if g = $10m/s^2$

1. 1.5 J

2. 2.0 J

3. 2.5 J

4. 3.0 J

Q.

When a 1.0 kg mass hangs attached to a spring of length 50 cm, the spring stretches by 2 cm. The mass is pulled down until the length of the spring becomes 60 cm. What is the amount of elastic energy stored in the spring in this condition, if g = $10m/s^2$

1. 1.5 J

2. 2.0 J

3. 2.5 J

4. 3.0 J

Q.

A body of mass 10 kg is dropped to the ground from a height of 10 metres. The work done by the gravitational force is $g=9.8m/se{c}^2$

1. - 490 Joules

2. + 490 Joules

3. - 980 Joules

4. + 980 Joules