Ch 3B Mass, Weight and Density#

Question 1

What is the SI unit for mass?

Answer 1

kg, kilogram

Question 2

What is the formula to find density?

Answer 2

desity=mass/volume

Question 3

What is the SI unit for weight?

Answer 3

N, newton

Question 4

What is the formula for weight?

Answer 4

W=mg

W: weight (N)

m: mass (kg)
g: gravitational field strength (10 N/kg on Earth)

Question 5

What is the value for gravitational field strength on earth?

Answer 5

10 N/kg

If you have learnt kinematics, you would have realised that the value of this g is the same as the acceleration due to gravity, g which is 10 m/s^2.

Question 6

Define mass.

Answer 6

The amount of matter in a body.

Question 7

Define weight.

Answer 7

The force of gravity acting on an object.

Question 8

What is the SI unit for density?

Answer 8

kg/m³

You have to be able to convert between kg/m3 and g/cm3.

Question 9

What are the differences between mass and weight?

There are 5 differences.

Answer 9

1) Mass is the amount of substance in the body. Weight is the force of gravity acting on the body
2) Mass is constant at any location. Weight depends on the acceleration due to gravity at the location.
3) Mass is a scalar quantity. Weight is a vector quantity.
4) Mass is measured in kilograms. Weight is measured in newtons.
5) Mass is measured using a beam balance. Weight is measured using a spring balance.