Math! please help!? i don't know how to solve this!?

Question

solve the equation w=cr^-2 for r.

suppose an object is 100 pounds when it it at sea level.

then for the equation find a value of c that makes the quation true. (sea level is 3963 miles from the center of the earth.)

then use the value of c you found in the previous question to determie how much the object would wiegh in:

a)death calley (282 feet below sea level.)

b)the top of Mt. Mkinly (20320 feet above sea level)

Answer 1

r^-2 = 1 over r^2 so you have w = c over r^2

multiply both sides by r^2: wr^2 = c

divide by w and take square root: r = √(c/w)

r = 3963

w = 100

so 100 = c(3963)^-2 ; divide both sides by 3963^-2 on a calculator and get

c = 1,570536,900

so plug in that for c and (3963-82/5280) for r for Death Valley, and (3963 + 20320/5280) for Mt McKinley

Answer 2

I can do the first part

w=c/r^2

r=sq rt c/w

Answer 3

Pay attention to th units of measure. You may have to convert from feet to miles several times in this assignment. You can use 1 mile= 5,280 feet for your conversions. Many people know that the weight of an object varies on different planets, but did you know that the weight of an earth also varies according to the elevation of the object? In particular, the weight of an object follows this equation:w+Cr^-2. where C is a constant, and r is the distance that the object is from the center of the earth.

a. Solve the equation w=Cr^-2 for r.

b. Suppose that an object is 100 pounds when it is at sea level. Find the value of C that makes the equation true. (Sea level is 3,963 miles from the center of the earth.)

c. Use the value of C you found in the previous question to determine how much the objec would weigh in

i. Death Valley (282 feet below sea level)

ii. The top o Mt McKinley (20,430 feet above sea level)

r^-2 = 1 over r^2 so you have w = c over r^2

multiply both sides by r^2: wr^2 = c

divide by w and take square root: r = √(c/w)

r = 3963

w = 100

so 100 = c(3963)^-2 ; divide both sides by 3963^-2 on a calculator and get

c = 1,570536,900

so plug in that for c and (3963-82/5280) for r for Death Valley, and (3963 + 20320/5280) for Mt McKinley

Answer 4

w = c/rr.

w/c = (c/rr)/c.

w/c = 1/rr.

c/w = rr/1.

c/w = rr.

root(c/w) = root rr.

plus or minus root(c/w) = r.