Use the table to answer the question.
Object Mass (grams)
table tennis ball 2.7
baseball 147.0
small rock 248.2
penny 2.5
A student drops the four objects listed from a height of 2 meters into a bucket of water. Which object will have the greatest kinetic energy?
Responses:
1) table tennis ball
2) baseball
3) penny
4) small rock
To determine the object with the greatest kinetic energy, we need to calculate the kinetic energy of each object using the formula:
Kinetic Energy = 1/2 * mass * velocity^2
Since the objects are dropped from a height of 2 meters, we can determine their velocity using the equation:
velocity = sqrt(2 * gravity * height)
where gravity is the acceleration due to gravity (approximately 9.8 m/s^2).
Let's calculate the kinetic energy for each object:
1) table tennis ball:
mass = 2.7 grams = 0.0027 kg
velocity = sqrt(2 * 9.8 * 2) = 6.26 m/s
Kinetic Energy = 1/2 * 0.0027 * (6.26)^2 = 0.042 J
2) baseball:
mass = 147.0 grams = 0.147 kg
velocity = sqrt(2 * 9.8 * 2) = 6.26 m/s
Kinetic Energy = 1/2 * 0.147 * (6.26)^2 = 0.344 J
3) penny:
mass = 2.5 grams = 0.0025 kg
velocity = sqrt(2 * 9.8 * 2) = 6.26 m/s
Kinetic Energy = 1/2 * 0.0025 * (6.26)^2 = 0.039 J
4) small rock:
mass = 248.2 grams = 0.2482 kg
velocity = sqrt(2 * 9.8 * 2) = 6.26 m/s
Kinetic Energy = 1/2 * 0.2482 * (6.26)^2 = 0.487 J
Therefore, the object with the greatest kinetic energy is the small rock, with a kinetic energy of 0.487 Joules. Answer: 4) small rock