12) A jet cruising at a speed of 1000 km/h ejects hot air in the opposite direction. If the speed of the hot air with respect to the jet is 800 km/h, then
A) find its speed with respect to the ground.
To find the speed of the hot air with respect to the ground, we can use the principle of velocity addition.
The velocity of the jet with respect to the ground is given as 1000 km/h.
The velocity of the hot air with respect to the jet is given as 800 km/h in the opposite direction.
To find the velocity of the hot air with respect to the ground, we can add the velocities of the jet and the hot air:
Velocity of hot air with respect to the ground = Velocity of jet with respect to the ground + Velocity of hot air with respect to the jet
Velocity of hot air with respect to the ground = 1000 km/h + (-800 km/h)
Since the hot air is being ejected in the opposite direction of the jet, we can subtract the velocities:
Velocity of hot air with respect to the ground = 1000 km/h - 800 km/h
Velocity of hot air with respect to the ground = 200 km/h
Therefore, the speed of the hot air with respect to the ground is 200 km/h.