Questions in Work, Energy and Power

Select	Question
	A force of $(3\,\hat i + 4\,\hat j)$ Newton acts on a body and displaces it by $(3\,\hat i + 4\hat j)\,m.$ The work done by the force is
	A 50kg man with 20kg load on his head climbs up 20 steps of 0.25m height each. The work done in climbing is
	A force $\vec F = 6\hat i + 2\hat j - 3\hat k$ acts on a particle and produces a displacement of $\vec s = 2\hat i - 3\hat j + x\hat k.$ If the work done is zero, the value of x is
	A particle moves from position ${\vec r_1} = \,3\hat i + 2\hat j - 6\hat k$ to position ${\vec r_2} = 14\hat i + 13\hat j + 9\hat k$ under the action of force $4\hat i + \hat j + 3\hat k\,N.$ The work done will be
	A force $(\vec F) = 3\hat i + c\hat j + 2\hat k$ acting on a particle causes a displacement: $(\vec s)\, = - 4\hat i + 2\hat j + 3\hat k$ in its own direction. If the work done is $6\,J,$ then the value of $'c'$ is
	In an explosion a body breaks up into two pieces of unequal masses. In this
	Which of the following is a unit of energy
	If force and displacement of particle in direction of force are doubled. Work would be
	A body of mass 5 kg is placed at the origin, and can move only on the x-axis. A force of 10 N is acting on it in a direction making an angle of ${60^o}$ with the x-axis and displaces it along the x-axis by 4 metres. The work done by the force is
	A force $\vec F = (5\hat i + 4\hat j)$ N acts on a body and produces a displacement $\vec S = (6\hat i - 5\hat j + 3\hat k)$m. The work done will be