When she reaches the top, she has more potential energy than she had at the bottom.
Potential energy = (mass) x (gravity) x (height)
= (40 kg) x (9.8 m/s²) x (5 m)
= 1,960 more joules .
Power = (energy) / (time)
= (1,960 joules) / (7 seconds)
= 280 watts
(about 0.375 horsepower)
Vt = Vboat - Vriver
Vt = 18 - 2.5 = 15.5 m/s
If the boat's direction is the same as the water, you sum the velocities of the river and the boat .
No the substance will remain the same substance as before.
Using the same antenna. Now he doesn't know if it was the antenna that caused the change in reception. so he wasn't only measuring the reception in his house he was measuring it based on different antennas
