Which of the following pairs of units are both SI base units?

Decimal sub-multiples and multiples of units are indicated using a prefix to the unit. For example, the prefix milli (m) represents 10^–3.
Which of the following gives the sub-multiples or multiples represented by pico (p) and giga (G)?

A metal sphere of radius r is dropped into a tank of water. As it sinks at speed v, it experiences a drag force F given by F = kr v, where k is a constant.
What are the SI base units of k?

In an experiment, a radio-controlled car takes 2.50 ± 0.05 s to travel 40.0 ± 0.1 m.
What is the car’s average speed and the uncertainty in this value?

What is equivalent to the unit of electric field strength? (E=F/q)

Which statement, involving multiples and sub-multiples of the base unit metre (m), is correct?

A student finds the density of a liquid by measuring its mass and its volume. The following is a summary of his measurements.
mass of empty beaker = (20 ± 1) g
mass of beaker + liquid = (70 ± 1) g
volume of liquid = (10.0 ± 0.6) cm^3

He correctly calculates the density of the liquid as 5.0 g cm^–3.

What is the uncertainty in this value?

A student uses a digital ammeter to measure a current. The reading of the ammeter is found to fluctuate between 1.98 A and 2.02 A.
The manufacturer of the ammeter states that any reading has a systematic uncertainty of ± 1 %.
Which value of current should be quoted by the student?

A metal sphere of radius r is dropped into a tank of water. As it sinks at speed v, it experiences a drag force F given by F = krv, where k is a constant.
What are the SI base units of k?