Unit 4 Newton's Laws

Units/Equations

100

What are the units for Force?

Newtons

200

What does the greek letter mu represent?

Coefficient of Friction

300

What is the equation for Newton's 2nd Law?

F=ma

400

What is the equation for weight?

W=mg

500

What is the equation for Friction force?

f(friction) = (mu)*Normal force

Concepts

100

Which value is always higher?  Static friction or kinetic friction?

Static

200

If we want to decrease the fricition of a surface, what must we do to the coefficient of friction of that surface? Increase or decrease?

decrease

300

A book slides across a table to the right. Which direction does the force of friction act?

Left

400

A box is sitting on a table.  What force is equal and opposite to the weight of the box?

Normal force.

500

What happens to the force of friction if the weight of an object doubles?

Force of friction also doubles.

Word Problems

100

A box on a table has a weight of 10N. What is the normal force of the table?

10N

200

A ball has an acceleration of 5m/s^2.  If it has a mass of 10kg, what was the force applied?

F = 50N

300

A force of 5N is applied to a mass of 5kg, what is the acceleration of the mass?

a = 1m/s^2

400

What is the weight of a box that has a mass of 10kg?

W = 98N

500

Daily Double

A man has a wieght of 400N.  His coefficient of friction between his shoes and the road is 0.5.  What is the frictional force?

Newton's 3 Laws

100

A soccer ball lies motionless on a field. It only starts rolling when a player kicks it. 

Which of Newton's 3 laws best describes this scenario?

1st

200

If you punch a wall the force the wall applies is the same amount of force back.

3rd law

300

When a bird flaps its wings downward, it rises into the air.

3rd

400

When you jump off a small boat into water, the boat moves backward.

3rd

500

It is easier to push a shopping cart that is empty compared to a full shopping cart.

2nd law.

The same force causes less acceleration with more mass.