# Calc

Newton's Law of Gravitation says that the magnitude F of the force exerted by a body of mass m on a body of mass M is the following.
F=(GmM)/r^2
Here G is the gravitational constant and r is the distance between the bodies.
(a) Find dF/dr

(b) Suppose it is known that Earth attracts an object with a force that decreases at the rate of 2 N/km when r = 30,000 km. How fast does this force change when r = 15,000 km?

1. π 0
2. π 0
3. π 106
1. dF/dr=-2GMm/r^3=-2F/r

b) dF/dr=-2 when r=30,000
but the relationship is inverse, so halving the distance will double the rate.

1. π 0
2. π 0
posted by bobpursley
2. 16

1. π 0
2. π 0
posted by Garrett

## Similar Questions

1. ### physics

Proponents of astrology claim that the positions of the planets at the time of a baby's birth will affect the life of that person in important ways. Some assert that this effect is due to gravity. Examine this claim with Newton's

asked by cb on March 14, 2009
2. ### calculus

newtons law of gravitation says that the magnitude F of the force exerted by a body of mass m on a bod of mass M is F=GmM/r^2 where G is the gravitational constant and r is the distance between the bodies. a)find dF/dr and explain

asked by cassie on October 12, 2007
3. ### Calculus

Okay so I have the following question and I am totally stuck: Newton's Law of Gravitation says that the magnitude F or the force exerted by a body of mass m on a body of mass M given by F=(GmM)/r^2 where G is the gravitational

asked by Tracy on October 12, 2006
4. ### physics

A uniform bar 25 meters long weighs 10,000 Newton's. From end A weight of 2500 Newton's is hung. At B the other end of the bar, there is a weight of 3500 Newton's. An upward force of 3000 Newton's is exerted 4 meters from B, while

asked by G on July 8, 2015
5. ### Physics

Two 200kg masses (400lb)are separated by a distance of 0.75m Using Newtons law of gravitation,find the magnitude of gravitational force exerted by one mass on the other.

asked by KerryAnn on October 1, 2018

i know this might seem kind of long. but if you could please help me, i'd greatly appreciate it. a. suppose you have a tug of war with a friend who is the same size and weight as you are. You both pull as hard as you can, but

asked by Tony on October 25, 2008
7. ### PHYSICS

Two crates , one with mass 4.00 kg and the other with 6.00 kg, sit on the frictionless surface of a frozen pond, connected by a light rope. Awoman wearing golf shoes(so she can get traction on the ice)pulls horizontally on the

asked by evelyn on March 4, 2012
8. ### physics question

I have a question about a problem regarding Newton's third law. a. An iron rod is held up by a magnet. The magnet is held up by a string (from a ceiling, let's say). Draw a free-body diagram for the magnet and a separate free-body

asked by Kim on November 21, 2006
9. ### physics

Based on the third law motion of equal and opposite forces, a mass should never accelerate because the net force on it will always be zero. Resolve the issue. would F=ma answer this question? If a force is exerted by object A on

asked by Benji on November 20, 2006
10. ### Physics

Calculate the percentage of Earthβs gravitational force on the ISS astronauts while orbiting at an altitude of 248 miles above Earthβs surface. To do this, compare the gravitational force on an orbiting astronaut to the force

asked by Haley on January 29, 2014

More Similar Questions