Answer:
B) Tommy had a positive acceleration between noon and 12:30 pm.
Explanation:
Acceleration is defined as the rate of change of velocity:
[tex]a=\frac{v-u}{t}[/tex]
where
v is the final velocity
u is the initial velocity
t is the time
In the problem,
- At noon, Tommy is walking at a velocity of 4 mi/h
- At 12.30 pm, Tommy is walking at a velocity of 6 mi/h
- A time of half an hour (0.5 h) passed between the two moments
So Tommy's acceleration is
[tex]a=\frac{6 mi/h-4 mi/h}{0.5 h}=4 mi/h^2[/tex]
and the acceleration is positive, since the velocity has increased.
