I just want to know the formula to use?

Question

A novice skier, starting from rest, slides down a frictionless 34.0° incline whose vertical height is 106 m. How fast is she going when she reaches the bottom?.

i was thinking about using K=1/2*mv^2 but we don't know the mass here or we can use w=m*g*h..

Answer 1

final velocity = sqrt(2*g*s) where g is gravitational accel and s is vertical distance.

I'll let you do the math.

Answer 2

First use sin(34 deg) to find the vertical drop for 106 meters on a 34 degree incline. Then, since there is no friction, the final velocity will be the same as the velocity due to gravity for the vertical drop. These formulas will be helpful: sin(A)= opp/hyp,
d = 1/2 g t(squared), v = at..

Answer 3

Acceleration on an incline:
acceleration (net) = a, a=g (sin (angle))

This will give you an answer in m/s^2. You will have to find the distance of the incline (hypotenuse) then multiple "a" and the hypotenuse. I believe this will give you a final velocity which is squared, and the answer should read V^2 = (answer m^2/s^2). If you take the sqaure root all the way across you should end up with an answer that will read V = answer meters/second.

I believe this is correct.

Answer 4

this is simple dude...
as the slope is frictionless..the only force acting on her is gravity, n dats vertically downwards

so, first calculate the distance she is gonna travel, ..which is the hypothenus of the right angled triangle

hence...distance = 106/cos(90-34) which is...= 189.56meters

now her acceleration along the slope
is gonna be 9.8xcos(90-34) = 5.48meters per second square

now...acceleration = velocity / time
integrating twice

distance = Uxt + 0.5x axt^2
whre U=initial speed, a=acceleration and t=time taken

hence...189.56 = 0xt + 0.5 x 5.48 x t^2
solving...
time taken to reach bottom is = 8.3176seconds

Answer 5

dude,
U should equate potential energy to kinetic energy. because at the end of of the hill, all her potential energy has been converted to kinetic energy. also, when u equate this 2 equations, the mass is irrelevant and gets cancelled out.

however, the velocity that you calculated from equating the 2 energies give u velocity in the direction of gravity.
Hence you need to do some vector calculation to determine the velocity along the 34 degrees plane.
cool?

Answer 6

What do you want to know? You should use m. You will use sin34 to find the force effects.

Answer 7

hmm i think there should be equation builder, paint brush and chart board to be able to answer these questions

Answer 8

Sorry.

TFTP