Question

A 20-kg child is tossed up into the air by her parent. The child is 2 meters off the ground traveling 5 m/s.

Circle one: KE / GPE / both

Show your work for finding the values of each type of energy the object has

Answer 1

Data:
m (mass) = 20 Kg
h (height) = 2 m
s (speed) = 5 m/s

`K_(E) = ?` kinetic energy (Joule)
GPE (Gravitational potential energy ) = ? (joule)
Both = KE + GPE = ?
Adopting: g (gravity) = 10 m/s²

Solving: (Kinetic Energy)

`K_(E) = (m*s^2)/(2)`

`K_(E) = (20*5^2)/(2)`

`K_(E) = (20*25)/(2)`

`K_(E) = (500)/(2)`

`\boxed{K_(E) = 250\:J}\end{array}}\qquad\quad\checkmark`

Solving: GPE

`GPE = m*g*h`

`GPE = 20*10*2`

`\boxed{GPE = 400\:J}\end{array}}\qquad\quad\checkmark`

Solving: Both (KE + GPE)

`Both = K_(E) + GPE`

`Both = 250+400`

`\boxed{Both = 650\:J}\end{array}}\qquad\quad\checkmark`