Preston Pushes a Wheelbarrow Weighing 490 N to the Top

question 19

Multiple Choice

Preston pushes a wheelbarrow weighing 490 N to the top of a 45.0-m ramp,inclined at 20.0° with the horizontal,and leaves it.Tamara accidentally bumps the wheelbarrow.It slides back down the ramp,during which an 80.0-N frictional force acts on it over the 45.0 m.What is the wheelbarrow's kinetic energy at the bottom at of the ramp? (g = 9.8 m/s²)

• A) 3,942 J
• B) 17,120 J
• C) 11,142 J
• D) 7,542 J
• E) ​1,231 J

---

Definitions:

Lightning Strike

A natural electrical discharge of very short duration and high voltage between a cloud and the ground or within a cloud.

Forest Fire

An uncontrolled fire that occurs in the wilderness, often in wooded areas, which can have both natural and human causes.

Tolerance

The capacity of an organism to endure exposure to a particular substance or environmental condition without adverse effects.

Hemlock

A type of plant belonging to the family Apiaceae, some species of which are toxic, and others, such as the trees in the genus Tsuga, are valuable timber resources.