Question

A micrometeor has a mass of 0.005 grams. When it enters Earth’s atmosphere, it travels at 21,000 meters per second. What is its kinetic energy when it enters Earth’s atmosphere?

KE=1/2 mv^2


(1 point)
Responses

0.0525 J
0.0525 J

1,102,500 J
1,102,500 J

1,102.5 J
1,102.5 J

2,205 J
2,205 J

Answer 1

Convert mass to kilograms: 0.005 g = 5.0×10^-6 kg.
KE = 1/2 m v^2 = 0.5(5.0×10^-6 kg)(21,000 m/s)^2
= 0.5(5.0×10^-6)(4.41×10^8)
= 1,102.5 J

Answer: 1,102.5 J.