KnowledgeMadeFun, home

Lesson · Grade 5 · Science

Power: How Fast Energy Is Transferred

  • Grade 5
  • Science
  • 1 min 7 s
  • British Columbia
  • BC5-SC-14

Two friends of the same weight climb the same hill: lifting each one takes the same energy, but the fast friend does it in 1 minute and the slow friend in 2 minutes, so the fast friend transfers that energy in half the time and uses twice the power. The video then shows that power is measured in watts, where 1 watt is 1 joule each second, using a 100 W motor and a 1000 W motor that can transfer 100 and 1000 joules each second.

Anyone can watch two lessons on the website without an account. Signing in is free, no payment and no card, and opens three a day; Plus has no limit.

Loading

Share to Google Classroom

In one sentence

The question this lesson answers

Two friends of the same weight climb the same hill.

If one friend is faster, who uses more power?

Transcript

What the lesson says

Two friends of the same weight climb the same hill.

If one friend is faster, who uses more power?

Lifting each friend up the same height takes the same energy.

The fast friend reaches the top in one minute.

The slow friend takes two minutes.

Power is how fast energy is transferred.

The fast friend transferred the same energy in half the time, so used twice the power.

Power is measured in watts, or W for short.

Motors and machines often show their power in watts.

One watt means one joule of energy transferred each second.

A 100 watt motor can transfer 100 joules of energy each second.

A 1000 watt motor can transfer ten times as much, 1000 joules each second.

Power is how much energy is transferred each second.

Curriculum

Where this fits

British Columbia, Grade 5

Science, Physics: power - the rate at which energy is transferredBC5-SC-14

Previous: Your Arm Is a Lever

The outcomes and strands follow the British Columbia curriculum.

Keep going

More on this topic