you have to substitiute volume of the ballon
A closed system is a system that is completely isolated from its environment. The physical universe, as we currently understand it, appears to be a closed system. An open system is a system that has flows of information, energy, and/or matter between the system and its environment, and which adapts to the exchange.
D makes the most sense, but you just have to put two and two together and go with your gut feeling, first cross out the answers that don't make sense (A didnt make sense) and go from there! I hope the little bit above me helped you answer or decide :) Good luck!
F=ma
As velocity is constant, a=0
So, F=0
Hope this helps!
Answer:
E) 800 km/h
Explanation:
The computation of the average vector velocity module of the plane, at that time is shown below:
The displacement vector is
d^2 = d1^2 + d2^2
where,
d1 = northeast displacement
d2 = southeast displacement
Now
d^2 = (120)^2 + (160)^2
= 14400 + 2560
= 40000
= √40000
d = 200 km
Now the average velocity is
V = ΔS ÷ Δt
= 200 ÷ 1 ÷ 4
= 200 × 4
= 800 km/h