A car travels along a straight line at a constant speed of 56.0 mi/h for a distance d and then another distance d in the same direction at another constant speed. The average velocity for the entire trip is 33.5 mi/h. (a) What is the constant speed with which the car moved during the second distance d?
I started out with Vxavg=(Vxi+Vxf)/2 and came out to 11 and it was wrong. If anyone has a good website I can use to learn physics it would be much appreciated.

Question

A car travels along a straight line at a constant speed of 56.0 mi/h for a distance d and then another distance d in the same direction at another constant speed. The average velocity for the entire trip is 33.5 mi/h. (a) What is the constant speed with which the car moved during the second distance d?
I started out with Vxavg=(Vxi+Vxf)/2 and came out to 11 and it was wrong. If anyone has a good website I can use to learn physics it would be much appreciated.

anonymous · Answer

@Shane_B  he told that that was wrong.....see his question

anonymous · Answer

Yup..!

anonymous · Answer

lol....i think the answer of mine was correct 23.98

anonymous · Answer

Use..thiss.....  2* v1 * v2 / (v2+v1) = V avg

anonymous · Answer

2*56* v2 / (v2+56) = 33.5

v2 = 23.94 m/s

anonymous · Answer

@Shane_B  u cant use that formula which u used becoz...the time intervals are not same

shane_b · Answer

After some more thought I agree with you...I oversimplified it.