Gravity and BalanceGravity and Balance

Newton’s Toy BoxNewton’s Toy Box

Activity 2Activity 2

VocabularyVocabulary

GravityGravity Gravity support forceGravity support force Newton (N)Newton (N) Pound (lb)Pound (lb) WeightWeight

What forces are acting on you right What forces are acting on you right now?now?

Gravity (pulling us downward to Gravity (pulling us downward to Earth)Earth)

Magnetism (Earth’s magnetic field)Magnetism (Earth’s magnetic field)

Are you actually falling at this Are you actually falling at this moment because of gravity force?moment because of gravity force?

No, there is a force that opposes No, there is a force that opposes gravity.gravity.

This force is called the gravity This force is called the gravity support force. This is an upward support force. This is an upward force.force.

Gravity support force is equal in Gravity support force is equal in strength to gravity’s downward pull. strength to gravity’s downward pull. These forces are balanced.These forces are balanced.

What is the source of gravity What is the source of gravity support force (sitting in your chair)?support force (sitting in your chair)? The chair and/or the floorThe chair and/or the floor

Is the force of gravity on you equal Is the force of gravity on you equal to the support force of the chair on to the support force of the chair on

you? How do you know?you? How do you know? Each of us is not moving; so, the two Each of us is not moving; so, the two

forces acting on each of us are forces acting on each of us are balanced.balanced.

What happens if a chair leg is weak What happens if a chair leg is weak and the chair cannot produce a and the chair cannot produce a

support force equal to your weight? support force equal to your weight? Why?Why?

The chair would break, and we would The chair would break, and we would fall to the ground. The two forces, fall to the ground. The two forces, gravity and the gravity support force, gravity and the gravity support force, would be unbalanced.would be unbalanced.

Activity Sheet 2Activity Sheet 2

We will be using a spring scale, We will be using a spring scale, wooden ball, and a bag.wooden ball, and a bag.

We will be working in groups of 4.We will be working in groups of 4. Read the activity sheet and begin the Read the activity sheet and begin the

activity.activity. Remember to read the scale on the Remember to read the scale on the

Newton side instead of grams.Newton side instead of grams.

Newton (N); Pound (lb)Newton (N); Pound (lb)

Newton is a metric unit of weight.Newton is a metric unit of weight. Pound is a standard or customary Pound is a standard or customary

unit of weight in the English system. unit of weight in the English system.

WeightWeight

Weight is the strength of the gravity Weight is the strength of the gravity force pulling down on an object.force pulling down on an object.

Exit Slip or HomeworkExit Slip or Homework

Architects and engineers must keep Architects and engineers must keep gravity in mind when they design gravity in mind when they design building. For example, the gravity building. For example, the gravity support force of the walls must be support force of the walls must be strong enough to hold up the roof. strong enough to hold up the roof.

Find examples in your neighborhoods Find examples in your neighborhoods where the gravity support force was where the gravity support force was not strong enough (hint: any object not strong enough (hint: any object that has collapsed)that has collapsed)