Answer:
Explanation:
a. GPE = mgh which is mass times gravity times height. For us, this is
GPE = 260(9.8)(5.0) so
GPE = 13000 J rounded to 2 sig fig's
b. is a little bit more involved, since we are on an incline. The formula for this is usually
[tex]wsin\theta-f=ma[/tex] where f is the pull of friction on the object. But we have no friction here, so f = 0. That means that we need to find the angle of inclination using right triangle trig. We have the height as 5.0 m and we have the length of the ramp as 13 m, so we an find the angle using the inverse sin button on our calculator.
[tex]sin\theta=\frac{5.0}{13}[/tex] so
[tex]\theta=23[/tex] degrees, rounded to 2 sig fig's as needed.
The formula to find Force is F = ma, which means we need the acceleration found in the equation
[tex]wsin\theta=ma[/tex]. Filling in:
weight = 9.8(260) = 2500 N so
2500sin23 = 260a and
a = 3.8 m/sec². Now we can find force:
F = 260(3.8) so
F = 990N
c. To life the piano straight up, we just need to overcome the pull of gravity along with the mass of the piano and the angle at which it is sitting. That has a formula of
Normal force = weight = wcosθ so
Normal force = 2500cos23 and
Normal force = 2300N
