Answer:
C Don't worry if you thought it was D. I almost answered that.
Explanation:
Remark
You can get this just by learning the vocabulary.
Efficiency = Work Out / Work In * 100%
Work in = 30J That's you swinging the hammer.
Work out = 10 J That's how much of the hammer's work gets to the nail.
Efficiency = (10/30)*100
Efficiency = 1/3 * 100
Efficiency = 33%
Baseball? ........................sorry if it’s wrong
Pitch. The vibration of the frequency gets higher and makes the pitch higher
Hi there!
Recall the equation for momentum:

p = momentum (kgm/s)
m = mass (kg)
v = velocity (m/s)
We can plug in the given values to solve for velocity:

The answer is A I believe. Hope this helps!