Question

1. the speed of a car traveling 200 meters in 10 seconds is equivalent to: *

a. 20 yards per second.
b. 2000 meters per second.
c. 72 kilometers per hour.
d. 115 miles per hour.

1. units of measurement used to label a quantity of acceleration are: *

a. cm2/sec.
b. sec2/cm.
c. cm/sec.
d. cm/sec2.

Explanation:

Step1: Calculate the speed in m/s

Speed \(v=\frac{d}{t}\), where \(d = 200\) meters and \(t=10\) seconds. So \(v=\frac{200}{10}=20\) m/s.

Step2: Convert m/s to km/h

We know that \(1\) m/s \(=3.6\) km/h. So \(v = 20\times3.6=72\) km/h.

Step3: Recall the formula for acceleration

Acceleration \(a=\frac{\Delta v}{\Delta t}\), where \(\Delta v\) is in units of length per time (e.g., cm/s) and \(\Delta t\) is in units of time (e.g., s). So the unit of acceleration is \(\frac{\text{cm/s}}{\text{s}}=\text{cm/s}^2\)

Answer:

For the first question: C. 72 kilometers per hour.
For the second question: D. cm/sec2.