This is the question I posted about two hours ago and I worked it out two ways-could you scroll down and check it, please?If I have a roller coaster, and hill 1 height is 50cm and hill height 2 is 25 cm and the PE is .9 as it approaches the top of hill 2, how do I calculate the speed.
Please help
Physics-Please help - bobpursley, Thursday, November 4, 2010 at 5:52pm
THe PE is .9 where? Where did the coaster start?
Physics-Please help - Joey, Thursday, November 4, 2010 at 5:54pm
The coaster started at .18PE-the .9 is the PE at the top of the second hill.The second hill is lower.
Physics-Please help - bobpursley, Thursday, November 4, 2010 at 6:01pm
Well, the difference in the two Potential energies is now KEnergy, 1/2 mv^2, solve for v.
Physics-Please check - Joey, Thursday, November 4, 2010 at 6:21pm
. The way to calculate this is you take the KE would be .9. You would say .9 = ½ (.035 x v^2) = 2.215. Correct or no?
Physics-Please check - Joey, Thursday, November 4, 2010 at 7:31pm
Should I have done this as 1/2mv^2 = mgh
Cross out like terms and get to v^2 = square root of 2 x g x .25m(h)= 2.125 m/s
Would this be correct?
I'm sorry, but I cannot scroll down and check previous conversations or calculations. However, I can help you understand how to calculate the speed of the roller coaster at the top of hill 2.
To calculate the speed (v), you need to use the conservation of mechanical energy. At hill 1, the potential energy (PE) will be equal to the kinetic energy (KE) of the roller coaster:
PE1 = KE1
Given that hill 1 has a height of 50cm, we can calculate the PE1 by multiplying the height (h1) by the mass (m) of the roller coaster and the acceleration due to gravity (g).
PE1 = mgh1
At the top of hill 2, the potential energy (PE2) will be equal to the kinetic energy (KE2) plus any energy losses due to friction or other factors:
PE2 = KE2 + losses
Given that the PE2 is 0.9 (assuming you provided the correct information), we can set up the equation as follows:
0.9 = 0.5mv^2 + losses
Now, we know that the losses in mechanical energy can be ignored in this case, as the coaster starts with an initial potential energy of 0.18. So we can neglect the "losses" term in the equation.
0.9 = 0.5mv^2
You can rearrange the equation to solve for the speed (v):
v^2 = (2 * PE2) / m
v = sqrt((2 * PE2) / m)
Given that the mass (m) of the roller coaster is not provided in the question, it is difficult to calculate the exact speed.