Science activity
How High Can You Jump? The Physics of Leaping
Jump as high as you can and notice that gravity always pulls you back down.
Materials and setup
- tape measure or ruler
- tape
- wall
- chalk or sticky note
- notebook
How this changes by age
Pre-K (ages 3–4)
Jump as high as you can and notice that gravity always pulls you back down.
Steps
- Jump up as high as you can! Watch what happens.
- Ask: What happened after you jumped? Did you stay up there or come back down?
- That pulling-you-down force is called gravity. It pulls everything toward the ground.
- Jump again! Every time, gravity brings you back.
- Ask: Why do you think gravity always pulls us down?
Learning objectives
- Observe that gravity pulls us back to Earth after jumping
- Be introduced to the word 'gravity'
Kindergarten (ages 5–6)
Learn that gravity is what makes you come back down after you jump.
Steps
- Jump as high as you can three times. Ask: Which jump was highest?
- Ask: What pulls you back down? (Gravity!)
- Try jumping from standing still vs. with a little run. Which sends you higher?
- Ask: Why do you think a running jump is higher than a standing jump?
Learning objectives
- Know that gravity pulls us back to Earth
- Observe that a running start increases jump height
Early elementary (ages 6–8)
Measure your vertical jump and learn how gravity and projectile motion determine how high you can go.
Steps
- Learn the concept: When you jump, you push down on the ground and the ground pushes you up (Newton's Third Law). Once you leave the ground, only gravity acts on you, pulling you back down at 9.8 m/s².
- Measure your vertical jump: Stand next to a wall and reach up as high as you can with chalk on your fingertip — mark the wall. Then jump and mark the highest point you reach. The difference is your vertical jump height.
- Try 5 jumps. Record each one. What was your best?
- Try with and without a small squat before jumping. Does bending your knees before jumping help?
- Gravity is the same for everyone: 9.8 m/s². So why can some people jump higher? (Hint: leg strength and technique.)
Learning objectives
- Measure vertical jump height quantitatively
- Understand that gravity (9.8 m/s²) acts equally on all jumpers
- Connect Newton's Third Law to the push-off phase of a jump
Upper elementary (ages 8–10)
Apply Newton's laws and projectile motion to analyze jumping, and research the physics behind athletic high jump records.
Steps
- Learn the physics: Force = mass × acceleration (Newton's Second Law). To jump higher, you need more force at takeoff relative to your body weight. Gravity pulls at 9.8 m/s² once you're airborne.
- Projectile motion: your jump follows a parabolic arc. Time in air is determined by how fast you push off vertically.
- Measure your vertical jump (see early-elementary method). Convert to meters. Calculate your hang time using: hang time = 2 × √(2h/g), where h = your jump height and g = 9.8 m/s².
- Research: Javier Sotomayor of Cuba holds the men's high jump world record at 2.45 meters, set in 1993. Calculate his approximate hang time using the formula.
- Research the Fosbury Flop: before 1968, high jumpers went over the bar face-down. Dick Fosbury went over backward (face up). Why does the Fosbury Flop allow athletes to jump higher even though their body's center of mass may actually go UNDER the bar?
- Write: 'The physics of jumping shows that...'
Learning objectives
- Apply F = ma and projectile motion to vertical jumping
- Calculate hang time from jump height using kinematics
- Know Javier Sotomayor's 2.45m world record (1993)
- Explain why the Fosbury Flop is biomechanically superior
Safety and evidence note
Read the full activity before beginning. An adult should supervise tools, heat, food, outdoor work, movement, and experiments as appropriate. Completion records that the activity was done; the child’s explanation, work sample, photo, or demonstration is stronger evidence of learning than a completion check alone.
Related science activities
Animal Body Language & Behavior
Animals talk all the time — they just don't use words. A dog wags its tail high and loose when it is happy, but tucks its tail between its legs when it is scared. A cat holds its tail straight up like a pole to say hello, but puffs it up like a bottle brush when it is startled. A bird sings soft songs on a calm morning, but makes a sharp 'chip-chip-chip' alarm call when something dangerous is near. If you watch closely, you can understand exactly what they are feeling.
Animal Habitat Diorama
Choose a favorite animal and build its home in a shoebox! Use natural materials, paper, and toy animals to create a habitat scene.
Animal Habitats & Needs
Here is an animal that will surprise you: the mantis shrimp can punch with the force of a bullet. It sees 16 types of color — humans only see 3. And it lives in a burrow it digs itself at the bottom of the ocean. When scientists first discovered how powerful the mantis shrimp's punch was, it shattered the equipment they were using to measure it. Every animal's body is perfectly matched to the place it lives. Today you'll discover how that matching works.
Animal Tracks & Signs
Look for clues that animals have been nearby! Find footprints, nests, holes, or chewed leaves.