**1.** How much is the work done in pulling up a block of wood weighing 2KN for alength of 10m on a smooth plane inclined at an angle of \(30^{0}\) with the horizontal ?

**A.** 1.732 KJ

**B.** 17.32 KJ

**C.** 10 KJ

**D.** 100 KJ

**Answer :** Option B

**Explanation :**

W=Fd cos\Theta

**2.** A force of 7N, making an angle \(Theta \)with the horizantal, acting on an object displacesit by 0.5m along the horizontal direction. If the object gains K.E. of 2J, what is thehorizontal component of the force ?

**A.** 2 N

**B.** 4 N

**C.** 1 N

**D.** 14 N

**Answer :** Option B

**Explanation :**

\(\Delta K=Fd cos\Theta = W\)

**3.** A 60 kg JATAN with 10 kg load on his head climbs 25 steps of 0.20m height each.what is the work done in climbing ? (g = 10 m/\(s^{2}\))

**A.** 5 J

**B.** 350 J

**C.** 100 J

**D.** 3500 J

**Answer :** Option D

**Explanation :**

\(W = Fd = (Mg)(d); where M= m_{1}+m_{2}\)

**4.** A ball of mass 5 kg is stiding on a plane with intial velocity of 10 m/s. If co-efficient of friction between surface and ball is \(\frac{1}{2}\), then before stopping it willdescribe...... (g = 10 m/\(s^{2}\))

**5.**

The relationship between force and position is shown in the figure given (in one dimensional case) calculate the work done by the force in displacing body from x = 0 cm to x = 5 cm

**6.** The force constant of a wire is K and that of the another wire is 3k when both the wires are stretched through same distance, if work done are \(W_{1}\)and \(W_{2}\), then..

**A.** \(w_{2}=3w_{1}^{2}\)

**B.** \(W_{2}=0.33W_{1}\)

**C.** \(W_{1}=W_{2}\)

**D.** \(W_{2}=3W_{1}\)

**Answer :** Option D

**7.** A ball is released from the top of a tower. what is the ratio of work done by forceof gravity in first, second and third second of the motion of the ball ?

**A.** 1 : 2 : 3

**B.** 1 : 4 : 9

**C.** 1 : 3 : 5

**D.** 1 : 5 : 3

**Answer :** Option C

**Explanation :**

\([h_{n} \alpha (2n-1)]\)

**8.** A spring of spring constatnt \(10^{3}\) N/m is stretched initially 4cm from the unstretched position. How much the work required to stretched it further by another5 cm ?

**A.** 6.5 NM

**B.** 2.5 NM

**C.** 3.25 NM

**D.** 6.75 NM

**Answer :** Option C

**Explanation :**

\(W=\frac{1}{2}k(x_{2}^{2}-X_{1}^2)\)

**9.** The mass of a car is 1000 kg. How much work is required to be done on it to make it move with a speed of 36 km/h ?

**A.** \(2.5\times 10^4 J\)

**B.** \(5\times 10^3 J\)

**C.** 500 J

**D.** \(5\times 10^4 J\)

**Answer :** Option D

**Explanation :**

According to work energy theorm \(W=\Delta k\)

**10.** A body of mass 6 kg is under a force, which causes a displacement in it given by \(S=\frac{2t^2}{3}\) (in m). Find the work done by the force in first one seconds.