This unit contains more equations but remember that the relationship sheet you are given during the exam will have these, so don’t panic if you forget one of them. The activity of a source drops from 4096 kBq to 1 kBq in 2 days. Calculate the half life of the source. Given that it takes 8 minutes for light to get from the sun, how far is it away is it from the Earth?

Some light sources emit only some wavelengths. They produce a line spectrum. Each line corresponds to a particular wavelength. The activity of a source drops from 448 kBq to 3.5 kBq in 17.5 years. Calculate the half life of the source.

National Qualifications

Can you use the kinetic theory of gases to describe the pressure-temperature, pressure-volume or volume-temperature relationships? If you are having difficulties with this, try reading this blog post. Use your knowledge of physics to comment on what the ball’s horizontal distance from the edge of the table would and would not depend on. All objects will acceleration due to gravity. On the Earth, close to the surface objects accelerate at 9.8 ms-2 . The alternative is to MULTIPLY the final activity by 2 n (2 to the power n where n is the number of half lives) There are useful set of series and parallel resistor activities here. Use the next button or follow links in the left sidebar to progress through the topic.

gravitational field strength, g, is the weight per unit mass. It is measured in Newtons per kilogram. It is the force of gravity or pull on each kilogram of mass. In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist manoeuvre, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft. This saves fuel, time, and expense. Gravity assistance can be used to increase or decrease its speed or redirect the path of a spacecraft. The “assist” is provided by the motion of the gravitating body as it pulls on the spacecraft. It was used by interplanetary probes from Mariner 10 onwards, including the two Voyager probes’ notable flybys of Jupiter and Saturn. Use the formula to find the number of half lives (this will be the number of arrows) No. of t ½ = time÷ t½ OR: Using your knowledge of physics, explain how NASA might know that the probe has now left our Solar System. A source has an activity of 30 kBq after being stored for 2 days. If the half life is 8 h, what was its initial activity?Now you’ve finished the electricity & energy unit, try some past paper questions from old credit & intermediate 2 exam papers. DOUBLE the final activity for the number of t ½ eg If you have 4 half lives double the final activity 4 times. NB DO NOT MULTIPLY BY 4