A relatively small impact crater 20 kilometers in diameter could be made by a co

Question

A relatively small impact crater 20 kilometers in diameter could be made by a comet 2 kilometers in diameter traveling at 28 km/s (2.8×104 m/s ).

A. Assume that the comet has a total mass of 4.2×10^12 kilograms. What is its total kinetic energy? (Hint: The kinetic energy is equal to 12mv2, where m is the comet's mass and v is its speed. If you use mass in kilograms and velocity in m/s, the answer for kinetic energy will have units of joules.)

B. Convert your answer from part A to an equivalent in megatons of TNT, the unit used for nuclear bombs. Comment on the degree of devastation the impact of such a comet could cause if it struck a populated region on Earth. (Hint: One megaton of TNT releases 4.2×10^15 joules of energy.)

Explanation / Answer

A) Kinetic energy of a body Ek = (1/2)mv2
where m = mass of the body = 4.2*1012kg
v = velocity = 2.8*104m/s
so Ek = 0.5*4.2*1012*(28*103)2
Ek = 1664*1018 = 1.6*1021 joules
B) 1 joul = 2.3900573613767*10-16 Mt
so 1.6*1021 joules = (1.6*1021)*2.3900573613767*10-16
= 3.82409177820272*105Mt

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.