Question

Please Help me with these two:

QUESTION 1

Let's say one of your runners moved from the 10 meter marked line to the 20 meter marked line in 3.5 seconds.

What was your runner's average velocity during that period of time (in m/s)?

(Enter your answer as a number only. No units or other text.)

QUESTION 2

Again, your runner ran between the 10 and 20 meter marks in 3.5 seconds.

Now let's say your runner hit the 15 meter mark (in between the 10 and 20 meter marks) at 2.7 seconds.

Did you runner acclerate or decelerate through the run (from the 10 meter mark to the 20 meter mark)?
a.

Had a constant velocity throughout the run.
b.

Accelerated throughout the run.
c.

Decelerate through the run.

Answer 1

See below.

Step-by-step explanation:

QUESTION 1: Distance travelled is

20m = 10 m = 10 m

The time taken was 3.5 sec

Average velocity = (10m)/(3.5s) = 2.86 m/s or 2.4 to 2 sig figs.

QUESTION 2: Again, your runner ran between the 10 and 20 meter marks in 3.5 seconds.

Average speed is 2.86 m/s

Now let's say your runner hit the 15 meter mark (in between the 10 and 20 meter marks) at 2.7 seconds.

Distance travelled = 15m - 10m = 5m

Velocity = 5m/2.86 sec or 1.75 m/s

Did you runner accelerate or decelerate through the run (from the 10 meter mark to the 20 meter mark)?a. Accelerated. The two speeds are different, The first speed is lower, so the runner was accelerating.

Had a constant velocity throughout the run. NO

b. Accelerated throughout the run. YES

c. Decelerate through the run. NO