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What's the difference between velocity and speed?

Velocity and speed and vector and scalar quanities respectively. Vector quantities have both direction and magnitude (size), whilst scalars only have magnitiude. It is important to distinguish between the tw...
MS
Answered by Mollie S. • Physics tutor
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A car's speed changes from 10m\s to 40m\s in 10 seconds. What is its acceleration?

Change in velocity is 30m/s Acceleration is equal to the change in velocity / time taken a = 30/10 = 3m/s 2
IR
Answered by Isabelle R. • Physics tutor
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a )John heats up 2kg of water from 20 degrees c to 80 degrees c. How much energy input did this require? b )When John weighs the water at the end, he has less than he started with. Why might this be? c) What hazards are in this experiment?

a) energy transferred = mass.specific heat capacity.temperature change, or E = m.c.theta. c is provided at 4181 joules per kg. so E = 2.4181.(80-20) = 501720 joules b) some water has evaporated off as it was...
RH
Answered by Ruth H. • Physics tutor
3580 Views

An Electric Kettle is used to boil water. After the water is boiled, the temperature of the water decreases by 22C. The mass of water in the kettle is 0.50 kg. The specific heat capacity of water is 4200 J/kg C. Calculate the energy transferred.

First, we need to recognise which equation to use. From the Physics Equation Sheet, we can see that the correct equation here is that dQ=m c dT, where dQ is the Energy transfer. Using this equation, we can s...
TJ
Answered by Tom J. • Physics tutor
28909 Views

Find the speed of a wave.

To solve that we get given that a wave generator produces three waves per second at a wavelenght of 1.2 meters. To tackle this you can use the formula v= f * lambda (speed = frequency * wavelength) In prepar...
MP
Answered by Max P. • Physics tutor
2782 Views