Chap 3: Dynamics I - Mass and Weight

Question 1

Define force

Answer 1

a push or a pull

Question 2

Effects of a force?

Answer 2

• change an object’s shape, size
• change object’s direction of motion
• move a stationary object
• stop a moving object

Question 3

Give examples of contact forces

Answer 3

• frictional force
• air resistance
• normal force
• tension

Question 4

Give examples of non-contact forces

Answer 4

• gravitational force
• electrostatic force
• magnetic force

Question 5

Define mass

Answer 5

a measure of the amount of matter in a body (kg)

Question 6

Is mass scalar or vector?

Answer 6

scalar quantity

Question 7

Does mass change depending on location?

Answer 7

No as it is not affected by gravitational field strength

Question 8

What instruments can be used to measure mass?

Answer 8

• beam balance
• calibrated electronic balance

Question 9

Define weight

Answer 9

gravitational force acting on an object (N)

Question 10

Is weight scalar or vector?

Answer 10

vector quantity

Question 11

Does weight change depending on location?

Answer 11

Yes as it is affected by gravitational field strength

Question 12

Instruments to measure weight?

Answer 12

spring balance

Question 13

What is gravitational field?

Answer 13

a region in which a mass experiences a force due to gravitational attraction

Question 14

What is gravitational field strength, g?

Answer 14

gravitational force per unit mass placed at a point (N/Kg)

Question 15

Is gravitational field strength a scalar or vector quantity?

Answer 15

vector quantity

Question 16

Gravitational field strength of Earth?

Answer 16

10N/Kg

Question 17

How to calculate weight from mass and gravitational field strength?

Answer 17

W = mg

Question 18

Another definition of gravitational field strength?

Answer 18

acceleration due to gravity