Units & Measurements Revision

What is the base unit for power?

• Js^-1

• kgm²s^-2

• kgms^-3

• kgm²s^-3

To obtain the period of the pendulum, Bob measures the time taken for the pendulum bob to travel from point A to point B.

He found that the average time taken for the bob to travel the distance is 2 seconds.

What is the period of the pendulum?

• 0.5 s

• 1 s

• 2 s

• 4 s

Which of the following pairs of units are measuring the same quantity?

• Js and W

• kgm²s² and J

• kgms^-2 and N

• kgs^-2 and Nm^-2

Bob wants to measure the thickness and the length of a skipping rope.

What instruments should he use?

• measuring tape and ruler

• micrometer and ruler

• micrometer and vernier calipers

• vernier calipers and measuring tape

Bob wants to find the radius of a ping pong ball.

Bob uses a pair of vernier calipers to measure the diameter of the ping pong ball.

The diagrams show the measurement of the zero error and the measurement of the diameter of the ping pong ball.

What is the radius of the ping pong ball?

• 1.96 cm

• 1.98 cm

• 3.92 cm

• 3.96 cm