Here, you can derive that by numerical method, as follows:
F = m.a
m = F/a
So, here we can see when we decrease one, other increase by same effect; we can say they are "Indirectly Proportional" to each other!
Hope this helps!
Answer: question 1 , would be one question 2 , would be 1 joule and number three would be number one and number four would be , power and last one would be, number two
Explanation: sorry if its wrong
The period T of a pendulum is given by:

where L is the length of the pendulum while

is the gravitational acceleration.
In the pendulum of the problem, one complete vibration takes exactly 0.200 s, this means its period is

. Using this data, we can solve the previous formula to find L:
Im not so sure but it should be the
instantaneous speed