Posted by Soly on .
Could you please check my work and help me with two of the problems.
An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the ground. If it instead flies into a 10 km/h headwind, its groundspeed is
100km/h10km/h = 90 km/h
The average speed of a horse that gallops a distance of 10 kilometers in a time of 30 minutes is? (This one I don't understand, I know the formula to find average speed is is average speed= distance traveled/time of travel)
What is the acceleration of a car that maintains a constant velocity of 100 km/hr for 10 seconds? (For this one don't I have to get the same units, this is how I started, but not too sure where to go afterward: (100 km/hr)(1000 km/hr)(1/3600 s)= 27.8 m/s)

Phyics Word Problems 
DrBob222,
The airplane problem is correct.The horse speed is 10 km/30 min which would make it 20 km/hr. That is solved as 10km/0.5hr = 20 km/hr. The problem doesn't ask for a particular unit.
The third problem I will leave for others.