The force that slows down a soccer ball rolling on the grass is the same force used to start a campfire. True or False
2 answers:
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Answer:
c.
Explanation:
- In absence of friction, total mechanical energy must be conserved.
- This means that the change in gravitational potential energy (in magnitude) must be equal to the change in kinetic energy:
- As it can be seen, the mass m is on the both sides of the equation, which means that it can be simplified.
- We can solve this equation for v (speed at the bottom) as follows:
- As it can be seen, the mass has no part in the equation, so, due both are starting from the same height, both people have the same speed at the bottom.
- The option c is the right one.
Answer:
Explanation:
recall that power is energy carried out or work done per time
P=W/t
P=2*10^6*35
t=6*60=420S
W=Energy
E=2*10^6*35*360S
E=25200000000
Energy stored by water from rest is called potential energy. Since the water is falling from a height , we calculate potential energy as thus
E=M*g*h
Assume that the water intakes are effectively 175 m above the electric generators. How much water must pass through the generators to power 2 million 35-W Las Vegas light bulbs for 6.0 minutes?
M=mass of water
g=acceleration due to gravity 9.81m/s^2
h=height ,175m
25200000000=M*9.81*175
M=
M=1716.75kg