For the work-energy theorem, the work needed to stop the bus is equal to its variation of kinetic energy:

where
W is the work
Kf is the final kinetic energy of the bus
Ki is the initial kinetic energy of the bus
Since the bus comes at rest, its final kinetic energy is zero:

, so the work done by the brakes to stop the bus is

And the work done is negative, because the force applied by the brake is in the opposite direction to that of the bus motion.
Needs are less than resources, and the population increases.
<span>Th find the average speed of a trip we need to dived the total distance by the total time.
Let's find the total distance d.
d = (300 mi/h)(2.00 h) + 750 miles
d = 600 miles + 750 miles
d = 1350 miles
The total distance is 1350 miles
Let's find the total time t.
t = 2.00 hours + (750 mi / 250 mi/h)
t = 2.00 hours + 3.00 hours
t = 5.00 hours
The total time of the trip is 5.00 hours.
We can find the average speed.
d / t = 1350 miles / 5.00 hours
d / t = 270 miles/ hour
The average speed of the trip is 270 mi/h
(Note that the direction does not matter when we find the average speed.)</span>
<span>B. If the temperature of a solid is increased, the solid expands and its volume increases.</span>