A cannon of weight 10 tonnes fires a shell of 50 kg with a muzzle velocity of 900 m/sec at an angle of 30?. The time taken for the shell to emerge from the barrel is 0.004 sec. The velocity of the cannon would be
A jet of water of cross-sectional area 20 sq. cm impinges on a plate at an angle of 60? with a velocity of 10 m/sec. Neglecting the friction between the jet and plate (density of water 1000/9.81 kgm-1 sec2 per cubic meter), the force exerted by the jet on the plate would be in the range
A body of weight W is resting at a plane inclined at 30? to the horizontal. It is attached to a string making an angle of 60? with horizontal. If the angle of friction be 30? the tension in the string would be
The moving parts of a machine which weigh 1 tonne perform vertical simple harmonic motion with an amplitude of 2.5 cm and a period of 0.5 sec. The base of the machine weighs 3 tonnes and rests on the ground. Maximum reactions on the ground would be
A man weighing 60 kg jumps on a vehicle of weight 240 kg moving with a velocity of 36 km/hours. The velocity of the vehicle after the man has jumped would be
