forces and acceleration

Question 1

Newton’s first law of motion

Answer 1

an object will remain at rest until acted on by an external force. an object in motion will remain in motion, same speed and direction.

Question 2

Newton’s second law of motion

Answer 2

If a resultant force acts on an object it will accelerate
F=ma

Question 3

Newton’s third law of motion

Answer 3

every action has an equal but opposite reaction

Question 4

force pairs

Answer 4

same type of force
act in the same line
opposite direction

Question 5

Resultant Force

Answer 5

Fnet
total force in a direction

Question 6

Elevator scenario F=ma

Answer 6

N = apparent weight
W = weight = mg
Fnet = resultant force
up: Fnet = N - W
ma = N - mg
N = ma + mg = m(a + g) = heavier
down: Fnet = N + W
ma = N + mg
N = ma - mg = m(a - g) = lighter

Question 7

Terminal velocity

Answer 7

when there is no resultant force and no acceleration. It is the maximum velocity a falling object can reach. Dependent on mass and surface area