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If the force between two point charges of charge 'Q1' and 'Q2' which are a distance 'r' apart is 'F' then what would the force be if the charge of 'Q1' is tripled and the distance between them doubled?

We know from Coulombs law that the force between two point charges is directly proportional to the product of the magnitudes of each charge and inversley proportional to the square of the distance between...

Answered by Joseph H. • Physics tutor

6709 Views

A gun of mass 10kg fires a bullet of mass 240g at a speed of 300ms-1. What is the speed of the gun's recoil?

First, convert the mass of the bullet into SI units -> 240g=0.24kg

The law of the conservation of momentum states that m₁v₁=m₂v₂. To find the speed of...

Answered by Jonny F. • Physics tutor

1969 Views

Derive an expression for the centripetal acceleration of a body in uniform circular motion.

(I assume familiarity with positions represented by vectors and differentiation of trigonometric functions). Consider the coordinates of a point moving in a circle of radius r around the origin. The equat...

Answered by Hubert A. • Physics tutor

3326 Views

The energy transferred from the water in the kettle to its surroundings in 2 hours is 46 200 J. The mass of water in the kettle is 0.50 kg. The specific heat capacity of water is 4200 J/kg °C. What is its temperature after 2 hours?

The water loses 4200 J/kg °C * 0.5 kg = 2100 J/°C

As it's lost 46,200 J in total (regardless of the time it took for this to happen), it must have reduced in temperature by 46,200 J / 2100 J/°C...

Answered by Dewi B. • Physics tutor

23535 Views

Explanation of alpha scattering experiment

Alpha particles which are made up of 2 protons and 2 neutrons (overall positive charge) are fired towards a thin sheet of gold. To ensure any deflection of the alpha particles is only due to the gold shee...

Answered by James M. • Physics tutor

13346 Views