Answer:
Coefficient of static friction will be equal to 0.642
Explanation:
We have given acceleration 
Acceleration due to gravity 
We have to find the coefficient of static friction between truck and a cabinet will
We know that acceleration is equal to
, here
is coefficient of static friction and g is acceleration due to gravity
So 
So coefficient of static friction will be equal to 0.642
Answer:
Net Force = 0
Explanation:
Causes objects to accelerate. Balanced Forces. Two equal forces push in opposite direction causing no change in motion causing net force = 0.
Yes. sound waves are produced by energy.
THE DOPPLER EFFECT. Anyways, it would have a higher whistle as it approaches you, when it gets to you it only gets quieter because it leaves after. Think of a motorcycle going by, its loud coming to you then as it passes it gets quieter.