A car travelling on a straight track accelerates uniformly from rest for 5.0 s and then travels at a constant speed for the next 5.0 s, covering a total distance of 75 m in that time. Determine the constant speed that the car achieved.

Question

A car travelling on a straight track accelerates uniformly from rest for 5.0 s and then travels at a constant speed for the next 5.0 s, covering a total distance of 75 m in that time.  Determine the constant speed that the car achieved.

A) 7.5 m/s
B) 10 m/s
C) 15 m/s
D) 20 m/s
E) 30 m/s

bobpursley · Answer

I wonder if "convering a total distance in that time" refers to the entire 10 seconds, or the last five seconds.

if the last five seconds
v=75/5=25m/s
if the entire ten seconds,
distance during the first five seconds is V/2 * 5=2.5V
75=2.5V+5V or V=10m/s

the physics kid · Answer

thanks bobpursley the correct answer is 10m/s i just didn't know how they got it. I Presumed that they were talking about the entire 10 seconds.