Physics Answers

The equation of discharge of a capacitor is given by Q = Qoe^(-t/RC) , define the terms half life and time constant of a discharging capacitor and derive the expression that links them.

A tyre of mass 15kg is suspended on a rope of length 7.5m and a girl of mass 75kg sits in the tyre. If the girls speed at the lowest point as she swings is 5m/s and the rope extends by 20cm, find the radius of this rope(young modulus = 2.0 x 10^11 Pa)

A tyre of mass 15kg is suspended on a rope of length 7.5m and a girl of mass 75kg sits in the tyre. If the girls speed at the lowest point as she swings is 5m/s and the rope extends by 20cm, find the radius of this rope(young modulus = 2.0 x 10^11 Pa)

A well lagged aluminium calorimeter of mass 80g contains 150g of water and 100g of ice at 0^oC. A heating coil rated 1.0kw is put in the calorimeter and the mixture is stirred until its temperature is 33^oC. Calculate how much ice is left after 1 minute. State any assumption you made.

A body of mass m wants to leave completely from the earths gravitational attraction, find the minimum speed it requires at the earth surface (escape velocity)

Consider a planet of mass M with an orbiting satellite at a distance of R from each of their centers. Show that Kepler's third law of gravitation is true.

An oscillatory motion has a period of 50.0s and an amplitude of 20.0cm. Determine its maximum acceleration and mechanical energy

The speed of light C is related to the permeability and thr permittivity e by the expression
C^2*uo*e = 1
(i) Show that this equation is homogenous
(ii) Calculate the value of uo