The graph between the resistive force F acting on a body and the distance covered by the body is shown in the figure. The mass of the body is 25 kg and initial velocity is 2 m/s. When the distance covered by the body is 4 m, its kinetic energy would be [This question includes concepts from Work, Energy & Power chapter]
1. 50 J
2. 40 J
3. 20 J
4. 10 J
The velocity, given to the block of mass (m), is to rotate it in a circle of radius l. Calculate the height (h) where the block leaves the circle.
1.
2.
3.
4. None of these
A steel wire can withstand a load up to 2940 N. A load of 150 kg is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position, so that the wire does not break when the load passes through the position of equilibrium, is (2008 E)
1. 30
2. 60
3. 80
4. 85
A body is displaced from (0,0) to (1m,1m) along the path x=y by a force . The work done by this force will be :
1.
2.
3.
4.
A weightless rod of length 2l carries two equal mass 'm', one tied at lower end A and the other at the middle of the rod at B. The rod can rotate in a vertical plane about a fixed horizontal axis passing through C. The rod is released from rest in the horizontal position. The speed of the mass B at the instant rod becomes vertical is:
(1)
(2)
(3)
(4)
Three different objects of mass and m3 are allowed to fall from rest and from the same point ‘O’ along three different frictionless paths. The speeds of the three objects, on reaching the ground, will be in the ratio of:
1.
2.
3. 1 : 1 : 1
4.
In a circus stuntman rides a motorbike in a circular track of radius R in the vertical plane. The minimum speed at highest point of track will be
(1)
(2) 2gR
(3)
(4)
A ball is suspended by a thread of length l. What minimum horizontal velocity has to be imparted to the ball for it to reach the height of the suspension:
(1) gl
(2) 2 gl
(3)
(4)
A body of mass m hangs at one end of a string of length l, the other end of which is fixed. It is given a horizontal velocity so that the string would just reach where it makes an angle of 60° with the vertical. The tension in the string at mean position is
(1) 2 mg
(2) mg
(3) 3 mg
(4)