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A 12V lamp, 36W is switched on for 1 hour. Find the energy supplied by the battery.

E = P*t = 36 * 3600 = 1.3 * 10⁵ J

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A student heats a bar of chocolate in the microwave for one minute. When they remove the bar they observe that there are patches of melted chocolate with unmelted chocolate between them. Suggest the mechanism of how this happens.

This question is about standing waves, the bar of chocolate melts only in the positions where antinodes are formed on the standing wave as they transfer the most energy as they have the greatest amplitude...

Answered by Haydn D. • Physics tutor

7126 Views

On the line of centres between the Earth and the Moon, there is a point where the net gravitational force is zero. Given that the distance between the two is 385,000 km, and that the Earth has a mass 81x that of the Moon, how far is this point from Earth?

Here, we must consider Newton's Law of Universal Gravitation. This states that the gravitational force acting between two bodies is proportional to the masses of each body and inversely proportional to th...

Answered by Phil R. • Physics tutor

6425 Views

Describe the basic principles of ultrasound imaging (2 marks)

Ultrasound is any frequency above that of human hearing - around 20 kilohertz.

Ultrasound imaging works by emitting a known intensity of ultrasound at a speci...

Answered by Alex G. • Physics tutor

2666 Views

Describe how the velocity and forces acting on a skydiver change during their fall (6 marks)

Different exam boards may want a different format of answer, so before beginning this question, it would be worth thinking how other six mark questions are marked in other papers.

Edexcel wan...

Answered by Jethro R. • Physics tutor

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