dann2707 Posted October 21, 2010 Report Share Posted October 21, 2010 (edited) Hey. Got this last question that's bugging the hella out of me. If anyone who's good at maths can throw me in the right direction I would seriously appreciate it. I've managed part i) ii) is the one giving me problems. Cheers in advance! Edited October 21, 2010 by dann2707 Quote Link to comment Share on other sites More sharing options...
AdamR28 Posted October 21, 2010 Report Share Posted October 21, 2010 Draw yourself another diagram for part 2, at the point where car 2 just starts to see car 1, you can then work out the angles and distances 1 Quote Link to comment Share on other sites More sharing options...
Tomm Posted October 21, 2010 Report Share Posted October 21, 2010 Spoiler alert: http://img.photobucket.com/albums/v427/tomnelson/index-2.jpg OK, start off looking at the red line. The angle between the top of the car on bridge and the crest of the road. You know it's 15m and 1.8m so you can calculate beta. Blue line: I've extended the horizontal of the bridge - the angle between this and the red line is also beta (opposite angle thing). Work out x (=180 - alpha - 90) x + beta + gamma = 90 degrees. You know x and beta so you can calculate gamma. Then finally the green bit - you can create yet another triangle that will be created when the driver coming up the slope reaches the point where he can just see the top of the other car. This triangle is bordered by the red line, green line(y) and the height of the driver's eyes (1.4m), with an angle of 90degrees from the slope of the incline. With gamma and the height (1.4m), you can calculate y. But you need to know how far UP the slope the car needs to go, so your answer is 50 - y EDIT: beaten 1 Quote Link to comment Share on other sites More sharing options...
dann2707 Posted October 21, 2010 Author Report Share Posted October 21, 2010 (edited) Thanks a lot for the answers! Very helpful indeed especially the diagram. I managed to get 38.41m up the slope for the final answer. Cheers again. Edited October 21, 2010 by dann2707 Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted October 21, 2010 Report Share Posted October 21, 2010 (edited) I think the answer is 32.6756m but am a bit rusty with geo. Edit: on my second go I got 32.96137m so who knows? Second edit:: came up with 32.96137m again.............maybe its right!! Edited October 21, 2010 by Matt Vandart Quote Link to comment Share on other sites More sharing options...
manuel Posted October 21, 2010 Report Share Posted October 21, 2010 I think the answer is 32.6756m but am a bit rusty with geo. Edit: on my second go I got 32.96137m so who knows? Second edit:: came up with 32.96137m again.............maybe its right!! not a particularly appropriate rounding though eh (assuming you have calculated correctly)? ... And in any case - questions like this are all about the working - who gives a shit about the actual number, any monkey can bash a keypad... Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted October 21, 2010 Report Share Posted October 21, 2010 (edited) Tomm has already detailed the working. Edit: 33m? Edited October 21, 2010 by Matt Vandart Quote Link to comment Share on other sites More sharing options...
Luke Rainbird Posted October 21, 2010 Report Share Posted October 21, 2010 As a general rule work as accurately as you can, but give your answers to the same sort of accuracy as the question is given (in this case to one decimal place) Quote Link to comment Share on other sites More sharing options...
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