acing cyclist is traveling at 15.3 km/h when she speeds up with a constant forward acceleration. After 5.00 s, her speed is 31.0 km/h. What is her acceleration?
3.14 km/h/s forward
4.90 km/h/s forward
23.2 km/h/s forward
27.0 km/h/s forward
a = dv/dt = (31-15.3)/5 = 3.14
To solve this problem, we can use the kinematic equation:
v = u + at
where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time.
Given:
Initial velocity (u) = 15.3 km/h
Final velocity (v) = 31.0 km/h
Time (t) = 5.00 s
Rearranging the equation, we can solve for the acceleration (a):
a = (v - u) / t
Substituting the given values:
a = (31.0 km/h - 15.3 km/h) / 5.00 s
Now let's calculate the acceleration:
a = 15.7 km/h / 5.00 s
To convert km/h to km/s, divide by 3600 (since there are 3600 seconds in an hour):
a = (15.7 km/h / 5.00 s) * (1 h/3600 s)
Simplifying:
a ≈ 0.004361 km/h/s
Therefore, the cyclist's acceleration is approximately 0.004361 km/h/s forward.
However, the given answer choices are in km/h/s, not km/h/s. To convert it to km/h/s, divide the result by 3600:
0.004361 km/h/s / 3600 = 0.000001211 km/h/s
Rounding to the appropriate number of significant figures, the acceleration is approximately 0.000001 km/h/s forward.
None of the given answer choices match this result, so it seems there is an error in the answer choices provided.