# Work Done, Varying Force and Path

## Trending Questions

**Q.**A bullet is fired from a gun. The force on the bullet is given by F = 600 - 2 × 105 t, where F is in Newton and t in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet

- 9 Ns
- Zero
- 0.9 Ns
- 1.8 Ns

**Q.**

A body of mass 3 kg is under a force, which causes a displacement in it is given by S=t33 (in m). Find the work done by the force in first 2 seconds

- 2 J
- 3.8 J
- 5.2 J
- 24 J

**Q.**The force exerted by a compression device is given by F(x)=kx(x−l), where l is the maximum possible compression, x is the compression and k is a constant. The work required to compress the device by a distance d will be maximum when

- d=l4
- d=l2
- d=l√2
- d=l

**Q.**A spring of spring constant 5×103 N/m is stretched initially by 5 cm from the unstretched position. The work required to further stretch the spring by another 5 cm is

- 6.25 J
- 12.50 J
- 18.75 J
- 25.00 J

**Q.**A block of 10 kg is pulled in a vertical plane along a frictionless surface in the form of an arc of a circle of radius 10 m. A force of 200 N is applied such that tension in the string always remains along the tangential direction as shown in figure. If the block started from rest at A, the velocity at B would be:

Consider π3=1 for calculation and take g=10 m/s2)

- 10√3 m/s
- 10 m/s
- 5√3 m/s
- 3√3 m/s

**Q.**An objects of mass 40kg having velocity 4^im/s collides with another object of mass 60kg having velocity 2^im/s. If collision is pefectly inelastic, then the loss of mechanical energy is

- 24J
- 96J
- 48J
- 6J

**Q.**A force F=−K(y^i−x^j), (where K is a positive constant) acts on a particle moving in the XY−plane. Starting from the origin, the particle is taken along the positive X−axis to the plane (a, 0) and then parallel to the Y−axis to the point (a, a). The total work done by the force F on the particle is

- −2Ka2
- 2Ka2
- −Ka2
- Ka2

**Q.**Assertion :A person working on a horizontal road with a load on his head does no work. Reason: No work is said to be done, if directions of force and displacement of load are perpendicular to each other.

- Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- Assertion is correct but Reason is incorrect
- Both Assertion and Reason are incorrect

**Q.**Consider a force →F=−x^i+y^j. The work done by this force in moving a particle from point A(1, 0) to B(0, 1) along the line segment is?

(all quantities are in SI units)

- 1
- 32
- 2
- 12

**Q.**A block of 10 kg is pulled in a vertical plane along a frictionless surface in the form of an arc of a circle of radius 10 m. A force of 200 N is applied such that tension in the string always remains along the tangential direction as shown in figure. If the block started from rest at A, the velocity at B would be:

Consider π3=1 for calculation and take g=10 m/s2)

- 10√3 m/s
- 10 m/s
- 5√3 m/s
- 3√3 m/s