56.3k views
0 votes
How fast (in m/s) must a 2,890 kg elephant move to have the same kinetic energy as a 68 kg sprinter running at 9 m/s?

User Msantos
by
7.4k points

1 Answer

3 votes

Final answer:

To have the same kinetic energy as a 68 kg sprinter running at 9 m/s, a 2,890 kg elephant must move at approximately 0.71 m/s.

Step-by-step explanation:

Determining the Speed of the Elephant to Match the Sprinter's Kinetic Energy

To calculate how fast a 2,890 kg elephant must move to have the same kinetic energy (KE) as a 68 kg sprinter running at 9 m/s, we use the formula for kinetic energy: KE = 1/2 × m × v^2, where m is mass and v is velocity. Given that the kinetic energies are equal, we set the kinetic energy of the sprinter equal to the kinetic energy of the elephant, solving for the elephant's velocity:
1/2 × (68 kg) × (9 m/s)^2 = 1/2 × (2,890 kg) × v^2

After simplifying and solving for v, the velocity of the elephant is:
v = sqrt((68 kg × (9 m/s)^2) / 2,890 kg)

When we calculate this, we find that the elephant must move at a velocity of approximately 0.71 m/s to match the kinetic energy of the sprinter running at 9 m/s.

User Ray Booysen
by
8.3k points