When an object has its motion
changed, the cause is generally an external force. The answer is letter A. It
follows Newton’s second law of motion wherein a body is at rest and remains at
rest without an external force applied to move the body.
Answer:
Notebook paper makes paper airplane fly farther
Explanation:
It's because paper airplane made of notebook is lighter and can fly far.
Answer:
The value is 
Explanation:
From the question we are told that
The weight of the block is 
The dimension of the block is 
Generally two atmosphere is equivalent to

Generally 1 atm = 
The area of the block would be evaluated using width and height because we need for the smaller surface to be in contact with the ground in order to maximize the pressure and minimize number of blocks
So

=> 
Generally the force due to this blocks is mathematically represented as

Here N is the number of blocks
So

=> 