Average speed =
(total distance covered)
divided by
(total time spent covering the distance)
Answer:
120 mph
Explanation:
Given:
Δx = 0.25 mi
v₀ = 0 mi/s
t = 15 s
Find: v
Δx = ½ (v + v₀) t
0.25 mi = ½ (v + 0 mi/s) (15 s)
v = 0.0333 mi/s
v = 120 mi/h
For this problem, we use the equations derived for rectilinear motion at constant acceleration. The equations are:
a = (v - v₀)/t
x = v₀t + 0.5at²
where
a is acceleration
v and v₀ are the final and initial velocities, respectively
x is the distance
t is the time
First, let's determine the a to be used in the second equation:
a = (7.5 m/s - 0 m/s)/1.7 s = 4.411 m/s²
x = (0)(1.7s) + 0.5(4.411 m/s²)(1.7 s)²
x = 6.375 m
