Gravity earth's radius question

  • Thread starter Thread starter physicshard22
  • Start date Start date
  • Tags Tags
    Gravity Radius
AI Thread Summary
The discussion revolves around calculating the force of gravity on an astronaut at a distance of 10 times the Earth's radius. The gravitational force formula used is F = Gm1m2/r^2. The initial force of gravity at the Earth's surface is given as 600N, leading to a calculation of 4.96N at the specified distance. There is clarification that the distance is measured from the center of the Earth, not the surface. The conclusion emphasizes the importance of understanding the correct reference point in gravitational calculations.
physicshard22
Messages
21
Reaction score
0

Homework Statement


The force of gravity on an astronaut is 600N at the Earth's surface. what is the force of gravity acting on him at a distance of 10 times the Earth's radius?



Homework Equations


F = Fm1m2/r^2


The Attempt at a Solution


F = Gm1m2/r^2
F = 600/11r^2
F = 4.96N

11r because its measured from the surface of the earth
 
Physics news on Phys.org
I think it means at a distance of 10 times R from the centre of the Earth. (not from the surface)
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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