Answer:
The frictional force
6.446 N
The acceleration of the block a = 6.04 
Explanation:
Mass of the block = 3.9 kg
°
= 0.22
(a). The frictional force is given by


3.9 × 9.81 × 
29.3 N
Therefore the frictional force
0.22 × 29.3
6.446 N
(b). Block acceleration is given by

F = 30 N
= 6.446 N
= 30 - 6.446
= 23.554 N
The net force acting on the block is given by

23.554 = 3.9 × a
a = 6.04 
This is the acceleration of the block.
Answer:
Explanation:
Given
mass of children 

distance between two children 
suppose small child is at a distance of x m from pivot point
so torque of small child and heavier child must be equal



We need a system to use those air vibrations to push against the surface of the inner ear fluid.
I believe it’s A. I know for sure it isn’t D.
Answer: two waves with identical crests and troughs meet
Explanation:
My teacher gave me the answer