Why do planets stay in orbit?
Show answer & explanation
Answer: Gravity balances velocity
Atmosphere creates drag — Wrong. Planets orbit in space (no atmosphere). Gravity pulls them toward the sun while their velocity keeps them moving sideways—stable orbit.
Gravity balances velocity ✓ — Correct! Planets orbit due to balance between gravity and inertia. Sun's gravity pulls planets inward (centripetal force). Planets' sideways velocity keeps them moving tangentially. Result: continuous free fall around the sun—orbit! Too slow = spiral in; too fast = escape. Kepler's laws describe orbital motion. Newton explained it's gravity providing the force. Curved spacetime (Einstein) is deeper explanation!
Space vacuum holds them — Wrong. Vacuum doesn't hold anything. Orbits result from gravity pulling planets toward the sun, balanced by their tangential velocity.
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