Answer:
20 hertz of frequency produced.
Explanation:

Here we will find frequency and period should be in second, here given: 0.05 seconds
using the formula:


Answer:
energy which a body possesses by virtue of being in motion.
Explanation:
As we know that friction force on box is given by

here we know that

here we have
m = 12 kg

so now we have

now we will have


so it required minimum 49 N(approx) force to move the block