Answer:
Explanation:
Ok, the average speed can be calculate with the next equation:
(1)
Basically the car cover the same distance "d" two times, but at different speeds, so:
and the total time would be the time t1 required to go from A to B plus the time t2 required to go back from B to A:
From basic physics we know:
so:
Using the previous information in equation (1)
Factoring:
(2)
Finally, replacing the data in (2)
Answer:
a) Ep = 5886[J]; b) v = 14[m/s]; c) W = 5886[J]; d) F = 1763.4[N]
Explanation:
a)
The potential energy can be found using the following expression, we will take the ground level as the reference point where the potential energy is equal to zero.
b)
Since energy is conserved, that is, potential energy is transformed into kinetic energy, the moment the harpsichord touches water, all potential energy is transformed into kinetic energy.
c)
The work is equal to
W = 5886 [J]
d)
We need to use the following equation and find the deceleration of the diver at the moment when he stops his velocity is zero.
By performing a sum of forces equal to the product of mass by acceleration (newton's second law), we can find the force that acts to reduce the speed of the diver to zero.
m*g - F = m*a
F = m*a - m*g
F = (60*39.2) - (60*9.81)
F = 1763.4 [N]