ok i need help on this other question
please
A 56.0 kg skier is at the top of a slope. At the initial point A, the skier is 14.0 m vertically above the final point B.
(a) find the difference in gravitational potential energy associated with the skier at the points A and B if the zero lever for gravitational potential energy is at ppoint B. answer in units of J
ok so this is what i did
PE = mgh
56kg(9.81)(14.0m)
=7691.04J
(B) find the difference in potential energy if the zero level is at point A. in units of J
(C) find the difference in potential energy if the zero level is midway down the slope at a height of 7.00m . in units of J
ok in parts B and C what does it mean to be at zero level?
i don't get it
zero level is where you measure from.
In b), the PE has decreased again (It went down).
In c), it still goes down,
PE= mg (H2-H1) Where H2 is the height from H2 to zero, and H1 is the height from zero.
In this context, the "zero level" refers to the reference point from which the gravitational potential energy is measured. It is the point where the gravitational potential energy is considered to be zero. In other words, it serves as a baseline against which the differences in potential energy at different points are measured.
Let's now solve the problem for parts (B) and (C) based on this understanding.
(B) To find the difference in potential energy if the zero level is at point A, we need to calculate the gravitational potential energy at both points A and B, and then find the difference between the two.
At point A:
PE(A) = mgh
= 56kg * 9.81 m/s^2 * 14.0m
= 7691.04 J
At point B:
Since the zero level is now at point A, the height at point B is 0m. Therefore, the potential energy at point B is zero.
The difference in potential energy is then:
Difference = PE(A) - PE(B)
= 7691.04 J - 0 J
= 7691.04 J
So, the difference in potential energy if the zero level is at point A is 7691.04 J.
(C) Similarly, to find the difference in potential energy if the zero level is midway down the slope at a height of 7.00m, we need to calculate the gravitational potential energy at both points A and B, taking into account the new zero level.
At point A:
PE(A) = mgh
= 56kg * 9.81 m/s^2 * 14.0m
= 7691.04 J
At the new zero level (midway down the slope at a height of 7.00m):
PE(Zero) = mgh
= 56kg * 9.81 m/s^2 * 7.00m
= 3843.36 J
At point B:
Since the zero level is now midway down the slope, the height at point B is 0m relative to the new zero level. Therefore, the potential energy at point B is also zero relative to the new zero level.
The difference in potential energy is then:
Difference = PE(A) - PE(B)
= 7691.04 J - 0 J
= 7691.04 J
So, the difference in potential energy if the zero level is midway down the slope at a height of 7.00m is also 7691.04 J.