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# Equations of Motion/ Projectile Problems ?

To kick a goal in rugby you must kick the ball over the crossbar of the goal posts (height 3m) between the two uprights. Evans attempts a kick from a distance of 35m. Initial Velocity is 20ms^-1 at 30 degrees to the horizontal. Ball aimed between uprights and no spin applied. i)How long does it take the ball to reach the goal posts? ii)Does it go over the crossbar? Later in game, Evans takes a nother kick from the same position and hits the crossbar iii) Given initial velocity was also 30 degrees to horizontal find initial speed Use g=10 ms^-2. A firework is buried so that its top is at ground level and it projects sparks all at a speed of 8 ms^-1 i) Calculate the height reached by a spark projected vertically and explain why no spark can reach a greater height ii) For a spark projected at 30 degrees horizontal over horizontal ground, show that its height in metres t seconds after projection is 4t-5t^2 and hence calculate the distance it lands from the firework. iii) For what angle of projection will a spark reach a maximum height of 2m ?

You probably need some sort of maths homework help website to have the best chance of getting such a detailed answer responded to.

However there is an outside chance someone will answer this in the comments section but in general this sort of question doesn't really have a good chance of getting answered.

By: knowitall
Replied at: 20 Mar 2011