Need help solving a homework problem: A shot-putter puts a shot (weight = 71.1N) that leaves hishand at a distance of 1.52 m above the ground. (a) Find the workdone by the gravitational force when the shot has risen to a heightof 2.13 m above the ground. Include the correct sign for the work.(b) Determine the change (PE=PEf -PE0)in the gravitational potential energy of the shot. Need help solving a homework problem: A shot-putter puts a shot (weight = 71.1N) that leaves hishand at a distance of 1.52 m above the ground. (a) Find the workdone by the gravitational force when the shot has risen to a heightof 2.13 m above the ground. Include the correct sign for the work.(b) Determine the change (PE=PEf -PE0)in the gravitational potential energy of the shot.
Explanation / Answer
weight W = 71.1 N mg =71.1 N Initial height h = 1.52 m Initial potential energy PEo= -mg h Since weight W is downward direction and displacement are inupward direction final height h ' = 2.13 m final potential energy PEf = - mg h ' Therefore the change (PE=PEf -PE0)in the gravitational potential energy of the shot = -mgh ' -( -mgh) =-mg ( h ' - h ) = -43.371 J