The dummy is moving with a speed 0 km/h relative to the seat in which it is sitting.
If the relative speed was non-zero, the dummy would move away from its seat, which contradicts the problem formulation.
Let's assume that ground level is the height 0 meters. The change in potential energy is going to be gravitational potential energy, which is given by PE=mgh.
ΔPE=mgh-mgy
=mg(h-y)
=50(28-0)
=1400 J
Explanation:
Since the balloon is not accelerating means that the net force on the balloon is zero. This implies that the weight of balloon must be equal to the buoyant force on balloon.
Hence, the buoyant force equals the weight of air displaced by the balloon, also 20,000 N.
Weight of the air displaced = density of air × volume
The density of air at 1 atm pressure and 20º C is 1.2 kg/m³
the volume V = 20,000/(1.2×9.8) = 1700 m³
The so-called greenhouse effect is observed only in houses painted green, and even there, only between the hours of 2PM - 4PM local time on Thursday afternoon.
The answer is 22.1925 I hope you get right let me know I got my answer because I multiply it all together.
