WBJEE 2013 LAST MINUTES SUGGESTION and PRACTICE SET SUBJECT:PHYSICS 1. A bard flies for 4 s with a velocity of |t-2| m/s in a straight line, where t=time in seconds. It covers a distance of a) 2 meters b) 3 meters c) 4 meters d) 5 meters Answer is : c) 4 meters 2. A projectile is moving at 60 m/s at its highest point, where it break into equal parts due to an internal explosion. One part moves vertically up at 50 m/s with respect to the ground. The other part will move at a) 130 m/s b) 120 m/s c) 110 m/s d) 100 m/s Answer is : a) 130 m/s 3. A ball falls vertically onto a floor, with momentum p, and then bounces repeatedly. The coefficient of resititution is e. The total momentum imparted by the ball to the floor is a) p(1+e)/(1-e) b) p(1+e) c) p(e+1)/e d) p/(1-e) Answer is : a) p(1+e)/(1-e) 4. A block of mass M is attached to the lower end of a vertical rope of mass m. An upward force P acts on the upper end of the rope. The system is free to move. ...
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