Oxygen is a gas a room temperature.
1.) The force of gravity is what we call weight, we define it as:
w=mg
w=5,7kg*9,8m/s²
w=55,86kg (b)
2.) We know that:
power=W/t
power=50J/20s
power=2,5Watts (a)
3.) The work done is equal to the potential energy, so:
Epg=mgh
Epg=63kg*9,8m/s²*7m
Epg=4321J
Now we get the power:
power=W/t
power=4321J/5s
power=864Watts
Now:
1HP=746Watts
=1,16HP (b)
4.) We know that:
F=ma
350N=m*10m/s²
m=350N/10m/s²
m=35kg (b)
5.) d.) Aceleration is tha rate of change in velocity, either positive (increasing) or negative (decreasing)