Gravity acceleration 1/5 earths, how high?

AI Thread Summary
To determine how high above Earth's surface gravity is one fifth of its surface value, one must consider the inverse square law of gravitation, which states that gravitational force decreases with the square of the distance from the center of the Earth. The acceleration due to gravity at a distance 'r' from the center can be expressed as g' = g / (r^2/R^2), where g is the surface gravity and R is the Earth's radius. Setting g' to one fifth of g allows for the calculation of the required distance from the center of the Earth. The problem emphasizes the need for initial thoughts and calculations to facilitate assistance. Understanding gravitational changes with distance is crucial for solving this problem effectively.
evan b
Messages
10
Reaction score
0

Homework Statement



How far above the Earth's surface will the acceleration of gravity be one fifth of what it is on the surface?
 
Physics news on Phys.org
We can only help those who help themselves. What thoughts have you had on the problem already? What work have you already done? Without this information, we cannot (and will not) help you.
 
Hoe does gravity falls off with distance ? Remember that distances are measured from the centre of the Earth
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top