A Tennis Ball Launcher Velocity Calculation
Understanding Momentum and Velocity in a Tennis Ball Launcher
A 20 kg tennis ball launcher shoots a 0.057 kg tennis ball across a frictionless court. If the tennis ball’s velocity after it is launched is 36 m/s to the north, what is the velocity of the tennis ball launcher?
The negative sign indicates that the velocity of the launcher is in the opposite direction of the tennis ball's velocity (south). After calculating the value, you will find the velocity of the 20 kg tennis ball launcher.
To determine the velocity of the tennis ball launcher, we can apply the law of conservation of momentum. This law states that the total momentum before an event is equal to the total momentum after the event, provided no external forces are acting on the system.
Before the launch, both the 20 kg tennis ball launcher and the 0.057 kg tennis ball are at rest, so the total initial momentum is zero. After the launch, the tennis ball has a velocity of 36 m/s to the north. We can find the final momentum of the launcher using the equation:
initial momentum = final momentum
0 = (mass of tennis ball)(velocity of tennis ball) + (mass of launcher)(velocity of launcher)
Substitute the given values:
0 = (0.057 kg)(36 m/s) + (20 kg)(velocity of launcher)
Solve for the velocity of the launcher:
velocity of launcher = -(0.057 kg * 36 m/s) / 20 kg
The negative sign indicates that the velocity of the launcher is in the opposite direction of the tennis ball's velocity (south). After calculating the value, you will find the velocity of the 20 kg tennis ball launcher.
What law is used to determine the velocity of the tennis ball launcher in this scenario?
The law used to determine the velocity of the tennis ball launcher in this scenario is the law of conservation of momentum.