2021 LSS2 P1

Which of the following are the correct instruments for measuring the mass and weight of an object?

• Mass - beam balance, Weight - electronic balance

• Mass - spring balance, Weight - beam balance

• Mass - spring balance, Weight - electronic balance

• Mass - electronic balance, Weight - spring balance

Two objects, A and B are placed on a balance scale. They are subsequently lowered into a container of water. What can be concluded about the above observation?

• The mass of A is greater than the mass of B.

• The mass of A is less than the mass of B.

• The volume of A is greater than the volume of B.

• The volume of A is less than the volume of B.

The diagram shows three forces acting on a box. What is the resultant force acting on the box?

• -23 N

• -1.0 N

• 29 N

• 53 N

Four different vases of equal masses are placed on the table. Which of the vases would exert the greatest pressure on the table?

• A

• B

• C

• D

A box of mass 600 g is pushed across a frictionless surface by a 20 N force for a distance of 60 cm. What is the work done on the box?

• 0.33 J

• 12 J

• 33.3 J

• 1 200 J

A rocket is fired vertically upwards. As it accelerates upwards after leaving the launch pad, which forms of energy are changing?

• Chemical energy, gravitational potential energy and kinetic energy

• Chemical energy and gravitational potential energy only

• Chemical energy and kinetic energy only

• Gravitational potential energy and kinetic energy only

The power rating of a dishwasher is 1400 W. It is used for 30 minutes each day. If the cost of electricity is $0.15 kWh, what is the cost of using the dishwasher for 20 days?

• $2.10

• $126

• $2 100

• $126 000

Which of the following diagrams of electrical plugs is correctly wired?

• A

• B

• C

• D

Which of the following surfaces is the worst emitter of heat energy?

• black and rough

• black and smooth

• white and rough

• white and smooth

Two plane mirrors are placed at 60° with each other. A ray of light incident on mirror AB is reflected to the second mirror BC. What is the angle of incidence of the ray at mirror BC?

• 5°

• 25°

• 35°

• 65°