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A body of mass 2kg is travelling in a straight line along the x-axis. It collides with a second body of mass 3kg which is moving at -2m/s. The two bodies move off together at 3m/s. What is the initial velocity of the first body?

2u-3 2=5 3=15, 2u=15+6. Therefore, u=10.5m/s. This is a standard type of question, it is simply about conservation of momentum. Momentum (p) is equal to mass velocity. Initially, the first body has momentum ...
CL
Answered by Caroline L. • Physics tutor
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What is the most effective use of the equation sheet?

When any question requires a formula, it is best to write down what is given to you in symbol form. You can then easily select the relevant equasions from the data sheet. Remember the multipliers! Take for e...
CW
Answered by Connor W. • Physics tutor
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What is the current in a circuit?

The current is the rate of flow of charge. It is a measure of how many electrons pass a point over a certain amount of time. We measure current using an ammeter which gives current in Amps. Current is usuall...
EJ
Answered by Emma J. • Physics tutor
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The energy of a photon is 1.5MeV. Calculate the frequency associated with this photon energy and state an appropriate unit in your answer.

E=1.5MeV = (1.5x10^6)(1.6x10^-19)J = 2.4x10^-13J E=hf, f=E/h = (2.4x10^-13)/(6.63x10^-34)=3.6x10^20Hz
TD
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A metal detector consists of a battery providing an alternating current to a transmitter coil and a receiver coil connected to a loudspeaker. Using Faraday's Law of Induction explain how a metal detector works. (5 marks)

The alternating current flows through the transmitted coil and produces a magnetic field around the coil. (1 mark) When the detector passes over a magnetic object, the magnetic field passes through the objec...
MH
Answered by Mabast H. • Physics tutor
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