Ms. Lawrence rode her bike up a hill at 8 miles per hour. She rode her bike down the hill at 16 miles per hour. What is the best prediction of her kinetic energy? KE= 1/2 mv^2
She had 4 times the kinetic energy going downhill as she d going uphill.
She had half the kinetic energy going downhill as she had going uphill.
She had the same amount of kinetic energy going uphill and downhill.
She had 2 times the kinetic energy going downhill as she had going uphill.
The best prediction of her kinetic energy would be that she had 2 times the kinetic energy going downhill as she had going uphill.
To calculate the kinetic energy, we use the formula KE = 1/2 mv^2, where m is the mass of the object and v is its velocity.
Since the mass of the bike remains constant, we can compare the kinetic energy based solely on the velocity:
For going uphill: KE1 = 1/2 m (8^2) = 32 m
For going downhill: KE2 = 1/2 m (16^2) = 128 m
Thus, the ratio of kinetic energies is KE2/KE1 = 128m/32m = 4
Therefore, she had 4 times the kinetic energy going downhill as she had going uphill.