Last question of homework, really don't understand it.
''An astronaut of mass 80kg stand on the horizontal floor of a spaceship moving vertically with acceleration a. If the acceleration due to gravity on the astronaut is g= 9.8 ms^-2, write a mathematical expression for and calculate the value of the reaction force R between the astronaut and the floor of the spaceship when:
1, a = 0;
2, a = 8 ms^2 upwards;
3, a = 8 ms^2 downwards.
Would be a real great help if someone could tell me what to do!
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- Thread Starter
- 29-09-2010 18:16
- 29-09-2010 21:10
This one needs to be in the physics section to get the best chance of replies.
However, as I'm here!
The key equation is F=ma where F is the resultant force acting on the astronaut.
The resultant force in each case will be the sum (or difference*) of the two forces we have here
his weight (mg) and
the reaction of the floor pushing up on him, R
The weight acts downwards and the reaction upwards so if one is positive the other is negative.
*If we let upwards be positive then the resultant force is always R-mg