Gravitational Force worksheets–> https://drive.google.com/drive/folders/1D_DFn2DipBeJTLYxJL7ypX6GgxZeepUo?usp=sharing

3-Day Lesson Plan: Gravitational Force

Day 1: Introduction to Gravity – The Universal Force

Objective:
Students will explain what gravitational force is and describe how it acts on objects with mass.

Standards Alignment:

• HS-PS2-4: Use mathematical representations of Newton’s Law of Gravitation to describe and predict the gravitational forces between objects.

Materials:

• Tennis ball & basketball (or similar objects of different mass)
• Whiteboard/markers
• Student notebooks

Activities:

1. Engage (5 min): Drop a tennis ball and a basketball at the same time — ask: Which will hit first? Why?
2. Explore (10 min): Students discuss everyday experiences with gravity (dropping objects, jumping, planets in orbit).
3. Explain (20 min): Direct instruction:
   • Gravity = attractive force between objects with mass.
   • Newton’s Law of Gravitation (conceptual, not heavy math yet).
   • Gravity depends on mass and distance.
4. Elaborate (15 min): Students draw concept maps showing connections between mass, distance, force, and motion.
5. Exit Ticket (5 min): Define gravitational force in your own words and give one example.

Homework:
Watch a short video on Newton’s law of universal gravitation and write down 2 questions you still have.

Day 2: Gravity in Action – Earth, Moon, and Orbits

Objective:
Students will analyze how gravitational force explains weight, planetary orbits, and tides.

Standards Alignment:

• HS-ESS1-4: Use mathematical or computational representations to predict the motion of orbiting objects in the solar system.

Materials:

• String & small ball (orbit demo)
• Chart paper
• Data table of planetary masses and distances from the Sun

Activities:

1. Engage (5 min): Quick demo: swing a ball tied to string in a circle (gravity = string’s force). Ask: What keeps the Moon in orbit?
2. Explore (15 min): In small groups, students compare Earth’s gravity vs. the Moon’s gravity (weight on Earth vs. weight on Moon).
3. Explain (20 min): Direct instruction:
   • Weight = force of gravity on mass.
   • Orbits result from inertia + gravity.
   • Tides caused by Moon’s gravitational pull.
4. Elaborate (15 min): Students use provided data to rank gravitational forces of different planets. Discuss patterns.
5. Exit Ticket (5 min): Why don’t planets crash into the Sun if gravity is pulling them inward?

Homework:
Worksheet: Calculate your weight on Earth, the Moon, and Jupiter (using given gravitational acceleration values).

Day 3: Applying Newton’s Law of Gravitation

Objective:
Students will apply Newton’s Universal Law of Gravitation to solve problems and make predictions.

Standards Alignment:

• HS-PS2-4: Use mathematical representations of Newton’s Law of Gravitation to describe and predict gravitational forces.

Materials:

• Calculator
• Worksheet with gravitational force problems
• Simulation (PhET Gravity Force Lab, optional if computers available)

Activities:

1. Engage (5 min): Show image of Earth orbiting the Sun. Ask: How strong is the gravitational pull between them?
2. Explore (10 min): Review formula: F=Gm1m2r2F = G \frac{m_1 m_2}{r^2}F=Gr2m1​m2​​ Define terms (G, m₁, m₂, r).
3. Explain (15 min): Teacher works through 1 example problem (e.g., gravitational force between Earth and Moon).
4. Elaborate (25 min): Students complete practice problems (pairs/groups). If available, use simulation to test how changing mass and distance affects force.
5. Evaluate (10 min): Mini-quiz: 2 calculation questions + 1 short-answer conceptual question.

Homework/Extension:
Write a short reflection: How would life on Earth be different if gravity were twice as strong? What if it were half as strong?