The driver of a 3000 lb. car, coasting down a hill, sees a red light at the bottom, and must stop. His speed when he applies the brakes is 60 mph, and he is 100 feet (vertically) above the bottom of the hill. (a)How much energy as heat must be dissipated by the brakes if we neglect wind resistance and other frictional effects

Explanation:

60 mph = 60 x 1760 x 3 / (60 x 60) ft /s

speed of car , v = 88 ft /s

kinetic energy of car = 1/2 m v²

= .5 x 3000 x 88²

= 11616 x 10³ poundal - foot

Potential energy = mgh

= 3000 x 32 x 100

=  9600 x 10³ poundal - foot

Total energy = potential energy + kinetic energy

= ( 11616 + 9600 )x 10³

= 21216 x 10³ poundal - foot .

This energy is dissipated as heat when brakes are applied on the car to stop the car .

whichever one it is, it's definitely not one that you included on the list you provided.

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.