Astronauts in orbit appear to be 'weightless'.Suppose an astronaut with a mass of 154 KG including gear is in orbit in the space shuttle, a distance of 222 km above the Earth;s surface.Taking the Earth's radius to be 6371km, and its mass to be 5.97 X 10^24,

A) What is the weight of the astronaut on Earth's surface?
B)What is the weight of the astronaut in orbit?
C) What do we mean when we say that an astronaut is weightless?

A) F = G m Me /r^2

at surface
G Me/r^2 = 9.81

B) answer to A*r^2/(r+222,000)^2
but if you try to measure it with a scale, zero because F is balanced exactly by mv^2/R
if in orbit which is the answer to part C. Really weight in orbit means nothing.

SO A= 222,000Kg?

Weight is NOT in kg but in Newtons !!!!!!

F = m * 9.81 = 154*9.81
= 1510 Newtons

and B =?

I did B

What did we get for B again final answer ?

a man drags a 72 kg sack of rice across a smooth floor with negligible friction. if the sack of rice accelerates horizontally at 6.40 m/s2 how much horizontal force doe man exert in dragging it