Newton's 2nd law can be expressed as the rate of change of the total momentum, respect of time, as follows:
So, in order to find the average force exerted by the skater on the wall, we can find the change in momentum due to the force exerted by the wall (which is equal and opposite to the one exerted by the skater), and divide it by the time interval , as follows:
Because there is no oxygen in space and we need oxygen to function so we need the suit to incapsulate us in oxygen so we can respire and so can our skin