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4.34 Buoyancy
4.35 Archimedes’ Law
4.36 Work
4.37 CALCULATINGWORK
4.38 Power
4.39 SIMPLEMACHINES
4.40 Efficiency
4.41 MECHANICALADVANTAGE
4.42 INCLINEDPLANE
4.43 Wedge
4.44 Screw
4.45 Lever
4.46 Wheel and Axle
4.47 Pulley
4.48 COMPOUNDMACHINE
4.49 References
Introduction
It’s a bird! It’s plane! It’s a super skateboarder! This boy appears to be flying high in the sky, but he can’t stay
airborne for long. Gravity will soon pull him back to the ground. How was he able to overcome the force of gravity
and rise into the air? In this unit, you’ll learn about forces such as gravity and motions such as skateboarding,
including how skateboarders can seem to defy gravity. Along the way, you can also pick up some cool skateboarding
tips!