A 400 g object is moving with a speed of 5 m/s. The kinetic energy of the object is . . . .

• 10 000 J

• 5 000 J

• 10 J

• 5 J

A coconut falls from a tree. The energy transformation that occurs is . . . .

• Potential energy decreases, kinetic energy increases, mechanical energy remains constant.

• Potential energy decreases, kinetic energy remains constant, mechanical energy increases.

• Potential energy increases, kinetic energy decreases, mechanical energy remains constant.

• Potential energy increases, kinetic energy decreases, mechanical energy increases.

A 0.5 kg mango is at a height of 10 m above the ground. If the gravitational acceleration = 10 m/s2, the potential energy of the mango is . . . .

• 0.5 J

• 5 J

• 50 J

• 500 J

A force of 20 N is applied to an object, causing it to move 75 cm. The work done by the force is

• 15 J

• 150 J

• 1500 J

• 15 000 J

An object with a mass of 250 kg is lifted vertically to a height of 60 m using a machine. If the machine's power is 1200 W, the time needed to lift the object is . . . seconds.

• 15 000

• 150 000

• 1250

• 125

The mechanical advantage of an inclined plane and the force required to move the object are . . . .

• 2 x, 500 N

• 2 x, 750 N

• 4 x, 750 N

• ½ x, 3000 N

To lift an object weighing 3,000 N using a pulley system, the minimum force required is . . . N.

• 750

• 1000

• 1500

• 3000

A lever is 4 m long and used to lift a stone weighing 1,200 N. The distance from the fulcrum to the stone is 80 cm. The force needed to lift the stone is . . . N.

• 600

• 400

• 300

• 240

Which of the following is an element?

• Table salt

• Water

• Carbon dioxide

• Oxygen

The following are compounds, except . . .

• Pure water

• Sulfuric acid

• Ammonia

• Air