After falling from rest at a height of 29.2 m, a 0.488 kg ball rebounds upward, reaching a height of 20.3 m. If the contact between ball and ground lasted 1.68 ms, what average force was exerted on the ball?
I'm so confused on where to start. tyvm
Calculate the momentum change due to the bounce.
Then use the relation:
Impulse = (avg. force)*(time) = momentum change
What do you mean by momentum? F=ma? thanks so much sorry to bother you
So glad someone is confused as I am! There are a lot of things on here that will not give you the write answer, but this will come pretty darn close!
There are four main calculations you need to make:
1) Find Velocity after falling (V1)
2) Find velocity on the way up again (V2)
3) Find the momentum change
4) Since (avg force)*(time)=momentum change, divide the change in momentum (found in #3) by the time to get average force.
DO NOT FORGET TO CHANGE YOUR TIME INTO SECONDS (divide ms by 1000).
For 1 & 2, use kinematic equation:
squarert: (2*9.8*Height) [9.8=gravitational acceleration]
For 3, use: m*(V1=V2)
For 4, use: momentum change/time in seconds
Hope this helps someone in the future!
To find the average force exerted on the ball, we can use the principle of conservation of energy. The initial potential energy of the ball (when it is at a height of 29.2 m) is equal to its final potential energy (when it reaches a height of 20.3 m) plus the work done by the average force during the contact with the ground.
Let's break down the steps to solve this problem:
1. Calculate the initial potential energy of the ball (PE_initial):
PE_initial = m * g * h_initial
where m is the mass of the ball (0.488 kg), g is the acceleration due to gravity (9.8 m/s^2), and h_initial is the initial height (29.2 m).
2. Calculate the final potential energy of the ball (PE_final):
PE_final = m * g * h_final
where h_final is the final height (20.3 m).
3. Calculate the change in potential energy (ΔPE):
ΔPE = PE_final - PE_initial
4. Calculate the work done by the average force (W):
W = ΔPE
5. Calculate the average force (F) using the work and contact time (Δt):
F = W / Δt
where Δt is the contact time (1.68 ms). Note that we need to convert it to seconds by dividing by 1000 (1 ms = 0.001 s).
By following these steps, you should be able to find the average force exerted on the ball. Let me know if you need help with any of the calculations.