Question

A bob of mass of 0.18 kilograms is released from a height of 45 meters above the ground level. What is the value of the kinetic energy gained by the bob at the ground level

Answer 1

Plug into the equation K=1/2mv^2 sooo.. (1/2)(.18)v(you don't have velocity so use the equation for potential energy because you haveheight)(U=mgh so (.18kg)(9.8m/s)(45)=U (set U equal to K)  
(.18)(9.8)(45m)=1/2(.18)v^2
solve for v
don't forget to take the square root of v