Let's assume that ground level is the height 0 meters. The change in potential energy is going to be gravitational potential energy, which is given by PE=mgh.
ΔPE=mgh-mgy
=mg(h-y)
=50(28-0)
=1400 J
An ampere (AM-pir), or amp
Answer:
35 km/hr
Explanation:
Average speed = (total of the speed)/(the sets of speeds given)
Direction does not matter in this instance since speed is only magnitude,
Average speed = (30 + 40)/2
Average speed = 70 ÷ 2
= 35 km/hr
Answer:
about 4.74 seconds
Explanation:
The time to fall distance d from height h is given by ...
t = √(2d/g)
t = √(2·110 m/(9.8 m/s^2)) ≈ 4.74 s
It will take the car about 4.74 seconds to fall 110 meters to the river.
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We assume the car's speed is horizontal, so does not add or subtract anything to/from the time to fall from the height.
