Forces in Nature

What is gravity?

• Gravity is a force that repels objects away from each other.

• Gravity is a force that only affects large objects.

• Gravity is a force that is caused by electromagnetic fields.

• Gravity is a force that attracts objects towards each other.

Which of the following is an example of gravity?

• An apple falling from a tree

• A fish swimming in water.

• A car speeding down a hill.

• A bird flying in the sky.

What is an air updraft?

• A current of air caused by the rotation of the Earth.

• A current of sinking air caused by the cooling of the Earth's surface.

• A current of rising air caused by the heating of the Earth's surface.

• A current of air caused by the movement of tectonic plates.

Which of the following is an example of an air updraft?

• tsunami

• hurricane

• tornado

• earthquake

What are opposing forces?

• Forces that act in the same direction and have equal magnitude.

• Forces that act in opposite directions and have different magnitudes.

• Forces that act in the same direction and have different magnitudes.

• Forces that act in opposite directions and have equal magnitude.

Which of the following is an example of opposing forces?

• Pushing a rock uphill

• Swimming against a strong current

• Tug of war

• Walking against a strong wind

What is the force that opposes motion?

• gravity

• inertia

• momentum

• friction

Which of the following is an example of friction?

• Rubbing your hands together

• Pouring water into a glass.

• Blowing air on a piece of paper.

• Walking on a slippery surface.

What happens when opposing forces are balanced?

• Equal forces

• Opposite forces

• No net force

• Net force

Which of the following demonstrates the concept of equilibrium?

• Rolling a ball down a hill

• Spinning a top

• Walking on a tightrope

• Throwing a frisbee

Answer explanation

Equilibrium is when two opposing forces exact the same amount of force on an object. If we were able to view this on a scale, it would show zero.