Which of the following has the largest kinetic energy?

A. a 10kg dog running down the street at 30mph

B. a tightrope walker slowly crossing niagara falls

C. a 0.02kg bullet moving down the barrel at 800mph

D. a semi truck parked in a parking lot

Question

Graham Bentley

Physics

21 November, 15:52

Which of the following has the largest kinetic energy?

A. a 10kg dog running down the street at 30mph

B. a tightrope walker slowly crossing niagara falls

C. a 0.02kg bullet moving down the barrel at 800mph

D. a semi truck parked in a parking lot

+1

Answers (1)

Know the Answer?

Austin Stein · Answer 1

Option C,

Reason

Kinetic energy is proportional to the square of velocity. Thus the higher the velocity the higher will be the kinetic energy

K. E. dog = 1/2 x 10 x (0.44704 x 30) ^2 m/s = 899.14 J

K. E. bullet = 1/2 x 0.02 x (0.44704 x 8000) ^2 m/s = 127,878 J

Which of the following has the largest kinetic energy?A. a 10kg dog running down the street at 30mphB. a tightrope walker slowly crossing niagara fallsC. a 0.02kg bullet moving down the barrel at 800mphD. a semi truck parked in a parking lot

Which of the following has the largest kinetic energy?

A. a 10kg dog running down the street at 30mph

B. a tightrope walker slowly crossing niagara falls

C. a 0.02kg bullet moving down the barrel at 800mph

D. a semi truck parked in a parking lot