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A tennis ball is hit over a net with a speed of 45ms^-1 and has a mass of 30g. Calculate the kinetic energy of tennis ball.

K=0.5 mv^2 K=0.5 0.03*(45^2) K=30.4J
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Answered by Liam M. • Physics tutor
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What is the amplitude and period of y=3sin(5x)?

Amplitude of a periodic function is the maximum height it reaches above the centre line (or the lowest). This expressed in the equation as '3'. If the 3 was not there, then the sin wave would have an amplitu...
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Answered by Madeleine R. • Maths tutor
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A rock has a mass of 100g and it is thrown across a pond at a speed of 30ms^-1. Calculate the de Broglie wavelength of the rock and explain whether you can see the wave produced.

λ=h/p λ=h/mv λ= 6.63 10^-34/0.1 30 λ= 2.21*10^-34m We cannot see the rock's de broglie wave because its wavelength is much smaller than that of the visible spectrum
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Answered by Liam M. • Physics tutor
3776 Views

Show that the radius of an orbit may be expressed as follows: R^3=((GM)/4*pi^2)T^2

Start with Newton's Law of Gravitation: F=(GMm)/R^2 (1) Since orbits are assumed to be circular recall the equation for centripetal force: F=(mv^2)/R (2) We can now equate these 2 forces due to them being ac...
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Answered by Liam M. • Physics tutor
6565 Views

How do I factorise and solve 2x^2+4x-6=0?

The 2 in front of the x^2 can cause confusion. In this case, the equation can be divided through by 2, to produce x^2+2x-3=0. From here it can be factorised by working out what adds to make '2' and times to ...
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Answered by Madeleine R. • Maths tutor
11318 Views