Question

A 4kg block which is initially at rest at the top of a friction less slope slides 30m down a frictionless slope . what is the kinetic energy of the block at the bottom of slope just before it hits the ground​

Answer 1

Answer:

(a) 25cm25cm

(b) 37.5cm37.5cm

(c) 62.5cm62.5cm

(d) None of the above

Answer : 

B

Solution : 

Wgravity=ΔUspringWgravity=ΔUspring

mgsinθ(d+0.25)=12k(0.25)2mgsinθ(d+0.25)=12k(0.25)2

which gives d=37.5cm