Lower Secondary: Mass, Weight and Density

What is the SI unit of mass?

(a)  

What is the approximate value of gravitational field strength on Earth?

• 10 N/kg

• 20 N/kg

• 100 N/kg

• 1000 N/kg

A man has a mass of 80 kg on Earth. What is his mass on the Moon?

• 80 kg

• 80 N

• 128 kg

• 800 kg

hich of the following represent the relationship between the mass of an object, its weight and the gravitational field strength.

• $weight=mass+g$

• $weight=mass\times g$

• $weight=mass\div g$

• $weight=mass-g$

Which of the formula is used to calculate the density of an object.

•  $\rho=m\times vol$ 

•  $\rho=\frac{m}{vol}$ 

•  $\rho=m+vol$ 

•  $\rho=m-vol$ 

Oil floats on water because

• oil is denser than water.

• oil is less denser than water.

• oil and water both have the same density.

Define the term mass of an object.

The mass of a steel hammer is 5 kg. What is its weight?

(gravitational field strength = 10 N/kg)

ANS: (a)   N

State the changes to its mass and weight, if there is any, when the same steel hammer is brought from Earth to the Moon.

The weight of a rock on the Earth is 80 N.

What is the weight of the rock on the Moon?

(gravitational field strength on Earth and Moon is 10 N/kg and 1.6 N/kg respectively)

ANS: (a)   N