The Sun has an energy output of 3.8 × 10²⁶ W. It has a radius of 7.0 × 10⁵ km. An estimate of the average power produced inside the Sun per m³ is:

The Earth has a mass of 6.0 × 10²⁴ kg and an orbital velocity of 30 km s^-1 about the Sun. What is its kinetic energy?

The second is now defined as the duration of 9,192,631,770 periods of radiation corresponding to the transition between two energy levels of the cesium 133 atom. What is the wavelength of the radiation emitted?

A neutron has a kinetic energy of 1.0 × 10^-7 eV. If moving vertically, how high could it rise in the earth’s gravitational field?

A steel ball-bearing is dropped onto a concrete floor and rebounds to 80% of its initial height. The percentage of the kinetic energy lost in the collision is.

The Moon takes 2 minutes to sink below the horizon at the equator when observed at night (about the same time as the Sun takes to set). If the radius of the Earth is 6400 km and the radius of the Moon is 1700 km, what is the angular size of the Earth when observed from the Moon?

A bubble is made from a soap film of uniform thickness enclosing a spherical volume of air. If the diameter of the bubble is trebled, the thickness of the soap film, t, will become

A 500-kg car is moving at 28 m/s. The driver sees a barrier ahead. If the car takes 95 meters to come to rest, what is the magnitude of the minimum average net force necessary to stop?

A block rests on an incline that makes the angle φ with the horizontal. The block remains at rest as φ is slowly increased. The magnitudes of the normal force and the static frictional force of the incline on the block

Contact forces are examples of which of the fundamental forces?

What net force is necessary to keep a 1.0 kg puck moving in a circle of radius 0.5 m on a horizontal frictionless surface with a speed of 2.0 m/s?

Two plane mirrors are at an angle of 15^o as shown in figure 1. A small object O is placed between them at an equal distance from mirror A and from mirror B. How many images can be seen (including the original)? (You can fit your eyeball between the mirrors if you want to)

A heavy piece of apparatus used to measure sea salinity is attached by a short rope to a flexible rubber balloon filled with air. The balloon should sit on the surface of the sea. On one occasion too little air is put in and the balloon sits just below the surface of the sea. The sea becomes rough and the balloon sinks down just a little further. What is likely to happen to the apparatus?

A tea urn has two elements used to heat the water; a slow one used for heating the full urn over a long period of time (taking  $t_1$ minutes) and a fast one used for heating the full urn quickly (taking  $t_2$ minutes). If both elements are used at the same time, how long will it now take to heat the full urn? 

A toy boat floats in a tank of water which is rather carefully balanced on a block of wood. If the boat slowly drifts to the right across the tank in the diagram below, what would likely happen to the tank of water in which it is floating?

A parsec is a unit of length used by astronomers to measure distance. If a parsec is 3.26 light years, and a light year is the distance that light travels in a year, how many metres are there in a parsec?

A Big Mac from McDonalds has an energy content of 2.3 MJ and a mass of 214 g whilst a tonne of TNT ( 1 tonne = 1000 kg) will release 4.7 GJ when detonated. Comparisons can be made by calculating the energy density, which is the amount of energy released in a reaction per unit mass. What is the ratio $\frac{energy\ density\ of\ a\ Big\ Mac}{energy\ density\ of\ TNT}$  

A cell which produces a potential E (called an emf) is shown in the diagram below and is connected to two resistors in series, a fixed resistor R₁ and a variable resistor R2. The current I in the circuit is measured by the ammeter A and the potential difference V across resistor R₂ is measured with the voltmeter V. The relation between the potential E and the current I is given by E = IR₁ + IR₂ Which of these graphs would produce a straight line fit?

A long uniform metal plate has a square hole cut in it. The plate is uniformly heated so that it expands a small amount. What is a correct statement about the hole now?

Three identical voltmeters each have a fixed resistance R which allows a small current to flow through them when they measure a potential difference in a circuit. The voltmeters, V₁, V₂, V₃ are connected in the circuit shown below. The voltage-current characteristics of the device D are unknown. If V₂ reads 2V and V₃ reads 3V, what is the reading on V₁?

A small mass, M, is given an initial velocity v₀, and it slides from A to B via two possible paths; either down the shallow dip X or over the hump Y, both of which are the same shape but inverted. Friction is to be ignored. Along which path does the mass take the shortest time to slide from A to B?