physics
posted by Jon .
1.
A European sports car dealer claims that his product will accelerate at a constant rate from rest to a speed of 81 km/hr in 10 seconds. What is the speed after the first 7 seconds of acceleration?
A) 157.5 m/s
B) 22.5 m/s
C) 56.7 m/s
D) 15.8 m/s
E) 32.1 m/s
Obviously, first convert to m/s.

yes convert km/hr to m/s.
Then acceleration is deltaV/time
speed= a*7 
okay, so d then :)