# The maximum speed you can walk on the Mars

## Homework Statement

You are an astronaut-in-training for the first mission to Mars by humans. You are about to go into a Mars simulator and need to know the answers to the following questions to complete the simulation correctly. You already have memorized basic information about Mars such as its mass (6.42x1023 kg), its radius (3.37x10^6 m) and its rotation period (its “day”) which is 24.8 hours. You also know that Newton’s universal gravitational constant (“big G”) is 6.67x10^-11 Nm2/kg2.

What is the speed at which you will be able to walk on the surface of Mars?

## Homework Equations

Fnet=N-mgM=mv2/r
vM=(gM r)(1/2)

F=GMMm/rM(1/2)=mgM
gM=GMM/rM1/2

## The Attempt at a Solution

use r= radius of the Mars, I got vM=3.56 km /s
use r= radius of my leg=0.7 m, I got vM=1.6 m/s.

Which one is right?

Last edited:

Andrew Mason
Homework Helper
Your problem refers to "the following questions" but there are none. What are questions?

AM

r is for the radius of Mars, your first equation uses it as the radius of the arc of the circle you move over.

Andrew Mason
Homework Helper
What limits the speed that you can walk on the surface?

Also the denominator is r^2 not r^1/2 in:

F=GMMm/rM2=mgM
gM=GMM/rM2

AM