A fitted brush called a draught excluder is placed along the bottom of a door. It keeps a room warmer by reducing energy loss by

A dog runs in a straight line to fetch a ball, waits, and then runs back to its owner. Fig. 1.1 shows the distance of the dog from its owner during the whole...

A student uses a displacement can to find the volume of a key. The key's mass is 47.4 g. Calculate its density.

The diagram shows a signal sent from a ground dish up to a communications satellite in orbit and then back down to a second dish on the far side of the world...

A hollow steel ship floats even though steel is far denser than water. Which statement explains this best?

Material Specific heat capacity / J/(kg °C) water 4200 aluminium 900 iron 450 copper 400 The table gives the specific heat capacity of four materials. For 1 ...

Substance Melting point / °C Boiling point / °C nitrogen −210 −196 oxygen −218 −183 mercury −39 357 sodium 98 883 The table gives the melting point and boili...

The diagram shows a microwave signal. Two complete waves fit into 6.0 cm, so the wavelength is 3.0 cm. Electromagnetic waves travel at 3.0 × 108 m/s. What is...

Fig. 1.1 shows part of a ticker tape pulled through a timer that prints 50 dots each second. The dots are evenly spaced and each gap between neighbouring dot...