Question

Jim is trying to improve his speed on the track so he can qualify for the State Championships. As he is running, he goes from 70 meters/minute (beginning speed) to 106 meters/minute (final speed) in 9 seconds. What is his acceleration?

Answer 1

Answer:

His acceleration is $\frac{1}{15}$ meters per seconds²

Step-by-step explanation:

Acceleration is the rate of change of the speed

The formula of acceleration is $a=\frac{v_{f}-v_{i}}{t}$ , where

• $v_{f}$ is the final speed
• $v_{i}$ is the initial speed
• The unit of the acceleration is meters/second²

∵ Jim goes from 70 meters/minute (beginning speed) to

   106 meters/minute (final speed) in 9 seconds

∴ His initial speed $v_{i}$ = 70 meters/minute

- Change it the meter per second

∵ 1 minute = 60 seconds

∴ $\frac{70}{(1)(60)}=\frac{70}{60}=\frac{7}{6}$  meters/second

∴ $v_{i}$ = $\frac{7}{6}$  meters/second

∵ His final speed $v_{f}$ = 106 meters/minute

- Change it the meter per second

∴ $\frac{106}{(1)(60)}=\frac{106}{60}=\frac{53}{30}$  meters/second

∴ $v_{f}$ = $\frac{53}{30}$  meters/second

∵ The time of the change of his speed is 9 seconds

∴ t = 9

∵ The formula of acceleration is $a=\frac{v_{f}-v_{i}}{t}$

- Substitute the values of t, $v_{i}$  and $v_{f}$ in the formula above

∴  $a=\frac{\frac{53}{30}-\frac{7}{6}}{9}=\frac{1}{15}$

∴ His acceleration is $\frac{1}{15}$ meters per seconds²