Question

Suppose a skydiver (mass = 75 kg) is falling toward the Earth. When the skydiver is 100 m above the Earth he is moving at 60 m/s. At this point calculate the skydiver’s Gravitational potential energy Kinetic energy Total mechanical energy

Answer 1

Answer:

  Potential energy = 73.575 kJ

  Kinetic energy = 135kJ

  Total mechanical energy = 208.575 kJ

Explanation:

   The potential energy of a body is given by the expression, PE = mgh, where m is the mass of the body, g is the acceleration due to gravity value and h is the height of the body.

  The kinetic energy of a body is given by $KE=\frac{1}{2} mv^2$, where v is the velocity and m is the mass of body.

  Total mechanical energy = Kinetic energy + Potential energy

  $KE=\frac{1}{2} mv^2=\frac{1}{2} *75*60^2= 135000J = 135kJ$

  PE = mgh = 75*9.81*100 = 73575 J = 73.575 kJ

  Total mechanical energy = Kinetic energy + Potential energy = 135+73.575

                                             = 208.575 kJ