Newton's Laws of Motion

It is more difficult to start a 50-kg box sliding across the floor than a 5-kg box because the 50-kg box has greater a. mass. b. inertia. c. volume. d. velocity.

A

When an action force occurs, the reaction force is always a. in the same direction as the action force. b. equal and opposite to the action force. c. applied to the same object as the action force. d. two of the above

B

Newton's First Law - Inertia

Inertia states that an object at rest stays at rest, an object in motion stays in motion

You know the mass of an object and the force applied to the object to make it move. Which of Newton's laws of motion will help you calculate the acceleration of the object?

Newton's Second Law

Acceleration Formula

acceleration = force/mass

A small child has a wagon with a mass of 10 kilograms. The child pulls on the wagon with a force of 2 newtons. What is the acceleration of the wagon?

acceleration = force/mass acceleration = 2 Newtons/10 kilograms

If you push a 20-kilogram mass with a force of 40 N, what will be the object's acceleration? a. 40 m/s2 b. 20 m/s2 c. 10 m/s2 d. 2 m/s2

acceleration = force/mass acceleration = 40 N/20 k = 20 m/s2 B

What is the rate of acceleration of a 2,O0O-kilogram truck if a force of 4,200 N is used to make it start moving forward?

acceleration = force/mass acceleration = 4200 Newtons/2000 kilograms

Newton's Second Law - Acceleration

an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. force = mass x acceleration

Distance Formula

distance = speed x time

Newton's Third Law: Action/Reaction

for every action (force) there is an equal and opposite reaction.

Force Formula

force = mass x acceleration

Your shopping cart has a mass of 65 kilograms, In order to accelerate the shopping cart down an aisle at 0.3 m/sec2, what force would you need to use or apply to the cart?

force = mass x acceleration force = 65 x 0.3 m/sec2

Mass Formula

mass = force / acceleration

What is the mass of an object that needs a force of 4,500 N to accelerate at a rate of 5m per second?

mass = force/acceleration mass = 4500 Newton/5 m per second

Speed Formula

speed = distance/time