Even though the object is weightless, it would need inertia, I.e, you pushing it or any form of transportation. So you would still have to push that 500kg to just keep it moving in space. Say if it were a planet with less gravitational force, it would be weightless.
No it will not because F will equal 3 not 0
Answer : The final temperature of the mixture is 
Explanation :
First we have to calculate the mass of water.
Mass = Density × Volume
Density of water = 1.00 g/mL
Mass = 1.00 g/mL × 180 cm³ = 180 g
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of hot water (liquid) = 
= specific heat of ice (solid)= 
= mass of hot water = 180 g
= mass of ice = 20 g
= final temperature of mixture = ?
= initial temperature of hot water = 
= initial temperature of ice = 
Now put all the given values in the above formula, we get


Therefore, the final temperature of the mixture is 
Using the kinematic equation,
v = u + at
26 = 11 + 3t
15 = 3t
t = 5 seconds.
Time required is 5 seconds.
A. Without doing much math, it can be seen from the graph that the altitude is decreasing. The slope of the position time graph determines velocity, so by comparing the start to the end of the graph, it can be seen that -100m was the change in altitude and 25 seconds was the change in time. Divide -100 by 25 to get -4m/s.