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Ch. 06 - Gravitation and Newton's Synthesis
Giancoli Douglas - Physics for Scientists and Engineers 5th edition
Giancoli Douglas5th editionPhysics for Scientists and EngineersISBN: 9780137488179Non è quello che usi tu?Cambia libro di testo
Capitolo 6, Problema 72a

A satellite circles a spherical planet of unknown mass in a circular orbit of radius 1.6 x 10⁷ m. The magnitude of the gravitational force exerted on the satellite by the planet is 120 N. What would be the magnitude of the gravitational force exerted on the satellite by the planet if the radius of the orbit were increased to 3.0 x 10⁷m?

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Step 1: Recall the formula for gravitational force: F=GmMr2, where F is the gravitational force, G is the gravitational constant, m is the mass of the satellite, M is the mass of the planet, and r is the radius of the orbit.
Step 2: Use the given data for the initial orbit to solve for the product GmM. Rearrange the formula to get GmM=Fr2. Substitute F=120 N and r=1.6×107 m into the equation.
Step 3: Calculate the new gravitational force when the radius of the orbit is increased to 3.0×107 m. Use the same formula, but now substitute the new radius into F=GmMr2. Use the value of GmM calculated in Step 2.
Step 4: Simplify the expression for the new force. Note that the gravitational force is inversely proportional to the square of the radius, so you can write Fnew=rold2rnew2. Substitute the old and new radii to find the ratio of the forces.
Step 5: Multiply the initial force (120 N) by the ratio calculated in Step 4 to determine the new gravitational force. This will give you the magnitude of the gravitational force exerted on the satellite by the planet at the new orbital radius.

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