Top answers

How do diodes work?

A diode is an electrical component in a circuit. It only allows electricity to flow in one direction. It can be used to change a current from alternating to direct.
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Answered by Samuel A. • Physics tutor
3369 Views

Can you please explain the basics of electricity? I can do the maths but I don't understand what 'voltage', 'current' or 'resistance' actually is!

The fundamental unit of electricity is 'charge'. Each electron is slightly negatively charged and it is this movement of charge around a circuit which powers our appliances. The speed of the electrons/the nu...
AM
Answered by Alex M. • Physics tutor
4083 Views

What are Newton's Laws of Motion?

Newtons First Law:An object at rest will stay at rest, and an object in motion will stay in constant motion unless acted upon by a resultant force Newtons Second Law:F=ma Newtons Third Law:If object A exerts...
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Answered by Husein A. • Physics tutor
2548 Views

A jug containing 0.250 kg of liquid is put into a refrigerator. Its temperature decreased from 20°C to 15°C. The amount of energy transferred from the liquid was 5,250 J. Calculate the specific heat capacity of the liquid.

Using the equation Q = mcT, where Q represents energy in Joules, m represents mass in kg, c represents specific heat capacity measure in joules kg -1 K -1 and lastly, T represents the change in temperature i...
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Answered by Andrew S. • Physics tutor
3254 Views

Using the principle of the conservation of energy, calculate the maximum speed of a ball of 5.0kg that has been dropped from a height of 20m. (Given that the gravitational field strength is equal to 9.8N/kg)

Answer: 20ms -1 The gravitational potential energy before the ball is dropped is equal to mgh. This gives the ball a maximum gravitational potential energy of 5.0kg * 9.8N/kg 20m which is equal to 980 J. At ...
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Answered by Charlie H. • Physics tutor
4092 Views