topic badge

3.05 Food and energy consumption

Interactive practice questions

An electronic road sign is powered by a small solar panel. It receives $0.007$0.007 kJ of energy from the sun for every second its directly shining on it.

a

How much energy in joules does the solar panel receive per second?

b

During the day a possum sits on top of the solar panel, completely blocking it for $50$50 seconds. How much energy did the panel miss out on in this time?

Give your answer in joules.

Easy
1min

The bicycle at the gym displays the estimated kilocalories that a person has used while on the machine. Peter was using the bicycle and used $537$537 kilocalories. How many kilojoules is this?

Use the approximate conversion rate of $1$1 kilocalorie$=$=$4.2$4.2 kilojoules.

Medium
< 1min

Gwen is training for a charity walk. In one of her training sessions she wants to burn $2352$2352 kilojoules. How many kilocalories does she have to burn?

Use the approximate conversion rate of $1$1 kilocalorie$=$=$4.2$4.2 kilojoules.

Medium
< 1min

Valentina calculates that by cycling to school each day she burns $2.5\times10^7$2.5×107 calories in a term.

Easy
1min
Sign up to access Practice Questions
Get full access to our content with a Mathspace account

What is Mathspace

About Mathspace