Peggy drives for 3 hours at an average speed of 61 miles per hour. Then when she crosses over into the next state she is able to drive the next 2.5 hours at an average speed of 72 miles per hour. what was her average speed for the entire trip?

65 miles per hour

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

angle efh= angle egh