Please help me. >.<

4. 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:

Respuesta :

Hi, thank you for posting your question here at Brainly.


The answer is both.


For kinetic energy:


KE = 1/2*m*v^2 = 0.5*20,000 grams*5 = 50,000 J


For gravitational potential energy:


Pe = mgh = 20,000 grams*9.81 m/s^2*2 m = 392.2 J



Answer:

both

KE = 250 J

PE = 392 J

Explanation:

Given that the child started resting, then after he was tossed up, he gained both, gravitational potential energy (now is in a higher position) and kinetic energy (his speed increase from 0 to 5 m/s).

Kinetic energy is calculated as follows:

KE = (1/2)*m*v^2

where m is mass and v is speed. Using mass in kg and speed in m/s, KE is in J.

KE = (1/2)*20*5^2 = 250 J

Gravitational potential energy is calculated as follows:

GPE = m*g*h

where g is the standard acceleration due to gravity = 9.8 m/(s^2) and h is height. Using mass in kg, g in m/(s^2), and h in m, GPE is in J.

GPE = 20*9.8*2 = 392 J