Physics Problem need help !?

"A physics professor did daredevil stunts in his spare time. His last stunt was an attempt to jump across a river on a motorcycle. (See the figure.) The takeoff ramp was inclined at 50.0 degress, the river was L= 37.0m wide, and the far bank was d = 19.0m lower than the top of the ramp. The river itself was H = 98.0m below the ramp. a. what should his speed have been at the top of the ramp for him to have just made it to the edge of the bank ? b. if his speed was only half the value found in part a, where did he land? can you please help me approach this problem and help me answer it. I don't know where to start"

6 replies

over 13 years ago

"20 kph won't get you very far from the ramp before you get wet... Let V be the speed up the ramp; Vv = the vertical component of the speed; Vh = the horizontal component. Vh = Vcos(50°), and Vv = Vsin(50°). The horizontal speed must be enough to just cover 37.0 m in t seconds, so t = (37.0 m)/(Vcos(50°)) s. The horizontal speed does not change, but the vertical speed is reduced by acceleration due to gravity: Vv = Vv0 - gt = Vsin(50°) m/s - (9.81 m/s²)((37.0 m)/(Vcos(50°) m/s)) = Vsin(50°) - 363/(Vcos(50°)) m/s. At the top of the flight, Vv = 0, so Vsin(50°) - 363/(Vcos(50°)) m/s = 0, so Vsin(50°) m/s = 363/(Vcos(50°)) m/s, so V² = 363/((sin(50°)(cos(50°)) m²/s², so V = 27.1 m/s. This speed is what is necessary to just reach the other bank (answer a)."

ekraj

about 13 years ago

"Make use of this formula to uncover no more.just one one particular. Versus= One.Third 12 = zero.forty-five. Radius Radius = 12/0.xlv Ur = 14/ (being unfaithful/something like 20) Radius = a dozen * thirty/ix S = lxxx/a few = twenty six.667 ohm ii. Electric resistance with the affair Ur = rho . Time-span / spot 80/3 = rho. three or more.half a dozen michael / ((xxii/seven * 8/something like 20 * 8/20)/myriad) eighty/three = rho. several.half-dozen l /77/2000000menqa_2 70/a few = rho. three.vi / nought.0000385 l Rho (impedance) =~ only two.8519 * 15^-5 various ohm.beat "

to see other 4 answers

I need help for this physics problem?

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albertein

over 13 years ago

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leonpan

over 13 years ago

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over 13 years ago

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blueeyes_11

over 13 years ago

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