# Newton's laws

## Homework Statement

(it's not about having the answer of the word problem question . i just want to clear some stuff out)
1.a car is going at a velocity of 43km/h and come to a stop of 35m
2. T or F question. Inertia is the result of stationary mass?
3. T of F question. an object will be at rest or slowing down if no force is acting on it.

## Homework Equations

1. when an object has constant velocity does it mean the force of friction = force applied?
meanning the force you exerted to an object equals to the amount of friction to come to a stop? is it true? for all the cases with constant velocity or does it depend on something?
2. it is ture that intertia is the result of stationary mass
3. It if false. it should be at rest or in uniform motion if no force is acting on it.

## Answers and Replies

When an object is moving at constant velocity, that means that the acceleration is zero, meaning that the net force is zero. In your first problem, what are all of the forces acting on the car? Add up the sum of the forces in the x component and the sum of the forces in the y component and set them both equal to zero. In this case, it is safe to neglect the y-component because there is no motion in the y-direction. So, the sum of the forces in the x = m*(acceleration in the x). This problem is exactly like your answer to number three.

so are you saying that is it correct that when it is at a constant velocity it means force applied= force of friction because it sums up to zero.