A spherical shell of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above, the ground. The velocity attained by the ball is :

A spherical shell of mass 20 kg is stationary at the top of a hill of

1.	A spherical shell of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above, the ground. The velocity attained by the ball is :
Answer» `40 m//s` `20 m//s` `10 m//s` `10sqrt(30 )m//s` SOLUTION :Loss in potential energy = Gain in K.E. `MG XX 80 = (1)/(2)mupsilon^(2)` ` IMPLIES upsilon^(2) = 2 xx 10 xx 80 = 1600` `impliesu= 40 m//s` HENCE choice is (a).

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A spherical shell of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above, the ground. The velocity attained by the ball is :

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