Question

An 80 kg skateboarder moving at 3 m/s pushes off with her back foot to move faster.

If her velocity increases to 5 m/s, what is her change in kinetic energy as a result?
 J
How much work did she perform?
 J
​

Answer 1

640 for both

Step-by-step explanation:

got right on edg

Answer 2

640 J

640 J

Step-by-step explanation:

ΔKE = ½ mv² − ½ mu²

ΔKE = ½ m (v² − u²)

ΔKE = ½ (80 kg) ((5 m/s)² − (3 m/s)²)

ΔKE = 640 J

Work = ΔE

Work = 640 J