PHYS 102 WEEK 1 QUIZ

PHYS 102 WEEK 1 QUIZ Q1 A long-distance runner has an average speed of 3 m/s during a race. How far does the runner travel in 39 minutes? Step 1: Write down what you know in symbolic form: Speed: v = 3 m/s Time: t = 39 min = 39 min x 60 s/min = 2,340 s. In physics we use the MKS system. Therefore, when solving problems your units need to be in M(meter(m))K(kilogram(kg))S(second(s)) units. Step 2: Write down what you don't know in symbolic form: How far (distance): d =? Step 3: Find an equation that contains what you know and what you don't know: d = vt Step 4: Solve the equation for what you don't know The equation is in the form we need. Step 5: Plug in (substitute) what you know and you will find out what you don't know: d = vt = 3 m/s x 2,340 s = 7,020 m. Managing units: (m/s) x s = ms/s = m (s/s) = m (since s/s = 1).