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Originally Posted by DazaiReta 1.How does the time of flight depend on the angle of elevation at projectile motion? Derive this formula, explain all the quantities and draw a picture to your answer. 
For questions like this, go back to basics. Think about the situation that's being presented to you and write down what's happening. The question mentions projectile motion... what is projectile motion? What objects are involved? What kind of equations do you need to worry about? The question asks you to draw a diagram, so you should have a go at drawing a diagram representing a situation. Once you have a basic idea of the situation, you should have an idea of how to piece the equations together to get a representation of the problem down on paper.
Do you have a scanner? If so, please give the question a go and upload a scan to this thread. Then we can get a better idea of how to help you.
2.What are the differences between mass and weight? Illustrate your answer with a picture and give examples.

What do you think? The questions says to draw a diagram.... what are your ideas on that front?
3.State the main assumptions of the ideal gas model. Explain them and draw a picture to illustrate your answer.

Have you looked up what an ideal gas is? Are gases in the real world ideal gases? Do you know what is meant by "assumptions"?
4.Write the formula for the first law of thermodynamics for an isothermal process. Explain the formula and all the quantities. Draw a picture to illustrate your answer.

Have a go...