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A strip of wood mass M and length l is placed on a smooth horizontal surface. An insect of mass m starts from rest at one end of the strip and walks to the other end in time t, moving with a constant speed. The speed of the insect as seen from the ground is [...]

Two ships are 10 km apart on a line joining south to north. The one farther north is seaming west at 20 km/h. The other is steaming north at 20 km/h. What is their distance of closest approach? Two ships are 10 km apart on a line joining south to north. The one farther north [...]

A block ‘A’ of mass m1 hits horizontally the rear side of a spring (ideal) attached to a block B of mass m^2 resting on a smooth horizontal surface. After hitting, ‘A’ gets attached to the spring. Some statements are given at any moment of time: i. If velocity of A is greater than B, [...]

Winds blows with a velocity x in the direction shown in Fig. 5.137. Two aeroplanes start out from point A and fly with a constant speed y. The first flies form A to B and the other along A to C. Both of them return back to A. Find the time an aeroplane having velocity [...]

Figure shows a hollow cube of side ‘a’ and volume ‘V’. There is a small chamber of volume V/4 in the cube as shown. The chamber is completely filled by in kg of water. Water leaks through a hole H and spreads in the whole cube. Then the work done by gravity in this process [...]

An aeroplane flies along a straight path A to B and returns back again. The distance between A and B is l and the aeroplane maintains the constant speed v w.r.t. wind. An aeroplane flies along a straight path A to B and returns back again. The distance between A and B is l and [...]

For the system shown in the figure, a small block of mass m and smooth irregular shaped block of mass M, both free to move are placed on a smooth horizontal plane. The minimum velocity v imparted to block so that it will overcome the highest point of M is a small block of mass [...]

A pilot is supposed to fly a certain distance AB, due east from A to B and then due west from B to A. The velocity of plane is v and that of air is u. The time for the round trip is t0 in still air. Show that A pilot is supposed to fly [...]

Two objects that are moving along an xy – plane on a frictionless floor collide. Assume that they form a closed, isolated system. The following table gives some some of the momentum components ( in kg m /s) before and after the collision. What are the missing values ( a, b )? B isolated system. [...]

To a man running upwards on the hill, the rain appears to fall vertically downwards with 4 m/s. The velocity vector of the man w.r.t. earth is (2i + 3j) m/s. If the man starts running down the hill with the same speed, the rain appears to fall vertically downwards with 4 m/s. The velocity [...]