1000*9.81 + 1000*1 = 10810 N
total mass = 1000 kg
F = 1000*10 + 1000 * 1 = 11,000 N
Ke on collision = m g h = m g (5)
so
(1/2) m v^2 = 5 m g
v^2 = 10 g
on rebound v^2 = 3.6 g
sqrt (3.6/10) = sqrt .36 = sqrt (36/100)
= 6/10 = 3/5
1.A lift weighting 1000kg is moving upwards with an acceleration of 1m/s^2.The tension in the supporting cable is
(a)980N (b)10800N (c)9800N (d)8800N
2.A person of mass 60kg is inside a lift of mass 940kg and presses the button on control panel.The starts moving upwards with an acceleration 1.0m/s^2.If g=10m/s^2,the tension in the supporting cable is
(a)8600N (b)9680N (c)11000N (d)1200N
3.A rubber ball is dropped from a height of 5 metre on a plane,where the acceleration due to gravity is not shown.On bouncing it rises to 1.8metre.The ball loses its velocity on bouncing by a factor of
(a)16/25(b)2/5(c)3/5(d)9/25
1 answer