Chapter 2: Introduction to Forces

Question 1

What is a force?

Answer 1

A force is something that changes an objects speed, shape or direction

Question 2

What are non-contact forces?

Answer 2

They are forces that act even when objects aren’t touching

Question 3

What are three examples of non-contact forces?

Answer 3

1. Gravitational forces
2. Electrostatic forces
3. Magnetic forces

Question 4

What are contact forces?

Answer 4

They are forces that only act when objects are in contact

Question 5

What is upthrust?

Answer 5

Upthrust is the upward force pushing up on any floating object

Question 6

What is reaction?

Answer 6

Reaction is the force that pushes back in response to another force

Question 7

What is a device for measuring force called?

Answer 7

A forcemeter

Question 8

What is the unit for measuring forces called?

Answer 8

Newtons

Question 9

What are the two factors of the force of gravity?

Answer 9

The mass of the two objects and how far apart they are.

Question 10

What is the force of gravity on an object called?

Answer 10

Weight

Question 11

What unit is mass measured in?

Answer 11

Kilograms

Question 12

What is a gravitation field?

Answer 12

It’s a region where a mass experiences force

Question 13

What is the gravitational field strength of earth?

Answer 13

10 newtons per kilogram

Question 14

How do you calculate weight?

Answer 14

Weight(N)= mass(kg) x gravitational field strength (N/Kg)

Question 15

What is air resistance?

Answer 15

Air resistance is the force of the air pushing back on you.

Question 16

What is the difference between weight and mass?

Answer 16

Mass is the amount of matter in an object while weight is the force it exerts.

Question 17

What is streamlining?

Answer 17

Streamlining is a method to reduce air resistance by reducing the area in contact with air.

Question 18

What factors affect air resistance?

Answer 18

1. The speed of the object
2. The area of the object

Question 19

Will heavier things fall faster in a vacuum?

Answer 19

No

the weight of an object doesn’t matter in a vacuum

Question 20

What is a force that keeps an object moving in a circle called?

Answer 20

A centripetal force.

Question 21

If a centripetal force stops acting on an object, what direction will it go in?

Answer 21

In the direction of it’s tangent.

meaning straight in the direction it was headed in.

Question 22

What are three forces which can have centripetal force?

Answer 22

1. Gravity
2. Friction
3. Tension