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Explain, in terms of the behaviour of molecules, how a gas exerts a pressure on the walls of its container. (4)

This question is 4 marks so you need to make at least 4 points. These types of questions just require memorising the 4 points: Lots of molecules collide with the walls. The molecules change momentum as they ...
JF
Answered by Jake F. • Physics tutor
25025 Views

Two cars are crash tested. Car A has a crumple zone, B doesn't. Both cars have mass 1500kg and a driver of mass 80kg and crash at 20m/s. Cars A and B take 0.8 and 0.2 seconds to stop respectively. Using this information, are crumple zones a necessity? (6)

We need to show that car A is safer than car B and this is done by showing that the force is greater on car B than car A. Start by finding the force on car A, total mass 1580kg: Force is the change of moment...
JF
Answered by Jake F. • Physics tutor
13616 Views

Mark has a voucher that gives him 22% off the prices at a hardware store. Estimate how much he will pay for an electric drill that normally costs £87.99. (non-calculator) (3)

It is important to remember this is an estimate, so we can simplify the numbers by saying they get 20% off and the drill costs £90. (1) 10% off would be £9, so 20% off is £18. (1) They have 20% off so they p...
JF
Answered by Jake F. • Maths tutor
4543 Views

Simplify (7+sqrt(5))/(sqrt(5)-1), leaving the answer in the form a+b*sqrt(5)

Step 1 - Identify the difference bet ween the required form of the answer and the expression to be simplified: It can be seen that in order to simplify the expression we need to somehow get rid of the denomi...
IR
Answered by Ian R. • Maths tutor
21991 Views

What is non-disjunction? How can this lead to changes in chromosome number?

Non-disjunction is the failure of chromosome pairs to separate properly during meiosis. This failure of separation usually occurs either in meiosis I (in anaphase I) or in meiosis II (in anaphase II). The co...
KW
Answered by Katy W. • Biology tutor
14662 Views