Answer:
T= 4.24sec
Explanation:
We are going to use the formula below to calculate.

Where T is period
L is length of rod
g is acceleration due to gravity =
From the problem, the rod is pivoted at 1/4L which means that three quarter of the rod was used for the oscillation. lets call this

= 4.4625m
thus
T= 4.24sec
Answer:
Maximum acceleration will be equal to 
Explanation:
We have given coefficient of kinetic friction 
And coefficient of static friction 
Acceleration due to gravity 
When truck moves maximum force will be equal to 
It is given that half of the weight is supported by its drive wheels
So force required 
From newtons law maximum acceleration will be equal to 
Mass × Velocity = Momentum
87 × 9 = 783 kg-m/s.☺
Objects can only go so fast and that speed is called terminal velocity. so the answer is A