Final Exam Science Grade 8

1 kg of object in the Earth’s gravitational force field experiences a force of about

• 7 N

• 9.8 N

• 20 N

• 100 N

As the distance between an object and the ground increases, the value of the gravitational field strength on the object

• also increases

• decreases

• remains constant

• may increase or decrease

A _________ _________ is the area around a magnet where there is a force pulling magnetic things to the magnet.

The ___________ is a measure of the ability of a force to turn or rotate an object on which it acts.

Work is measured in the unit known as

• Newton

• Watt

• Joule

• Calorie

Power is measured in the unit known as

• Newton

• Joule

• Calorie

• Watt

A worker can carry 3 bags of cement vertically through a distance of 15 m in 3 minutes. Each bag has a mass of 10 kg. Calculate his power. (g=10 N/kg)

• 25 w

• 50 w

• 500 w

• 1500 w

…………………is the ability to do work.

• Power

• Energy

• Simple machine

• The law of conservation

In science, __________ is defined as the product of the force and the displacement of an object in the direction of the force.

A boy pushes a trolley with a horizontal force of 20 N. The trolley moves 5 m horizontally. What is the work done?

• 4 J

• 100 J

• 4 J/s

• 100 J/s