Calculating Mass of an Astronaut in a Rocket with Two Accelerations

[Moninder]

Homework Statement

An astronaut who is weighing himself inside of a rocket blasting off from the moon with an upward acceleration of 1.26m/s^2 records a scale reading of 188N . The acceleration due to gravity on the moon is 1.67m/s^2 .
Find the mass of the astronaut

Homework Equations

F=ma

The Attempt at a Solution

I subtracted the accelerations to m=188N/(1.67-1.26) and it wasn't the answer, I also tried them individually and still can figure it out. m= 188N/1.67 and m=188N/1.26

 

[cepheid]

Draw a free body diagram for the astronaut. The astronaut has two vertical forces acting on him, the normal force F_N upward (from the scale, which is also what the scale measures), and his weight F_g, downwards, which is the force with which the moon's gravity pulls on him.

Since the astronaut has a non-zero upward acceleration a = 1.26 m/s², Newton's 2nd law says that there is a NET upward force acting on him. In other words, the sum of all vertical forces must be an upward force ma.

F_net = ma

ƩF = ma

F_N + F_g = ma

The gravitational force Fg is equal to -mg, with the negative sign because the force acts downwards. On the moon, g = 1.67 m/s².

F_N - mg = ma

Can you take it from here?

 

[Moninder]

oooooo now i get it, thanks