Question

Luna and Angela are competitors in a running competition. Both are leading the race and enter at the same time the last 30 meters. Angela enters the final segment runnning at 4 m/s and "applies" an acceleration of 2 m/s2 while Luna enters the final segment at 3m/s but "applies " an acceleration of 3 m/s2. (a) Who finishes the race first? (Do the calculations) (b) Who is running faster at the end of the race?

Answer 1

(a) Luna

(b) Luna

Step-by-step explanation:

(b)

The final speed can be found by using the third equation of motion:

where,

a = acceleration

s = distance covered

vf = final speed

vi = initial speed

For Angela:

a = 2 m/s²

s = 30 m

vi = 4 m/s

vf = v_fa

therefore,

For Luna:

a = 3 m/s²

s = 30 m

vi = 3 m/s

vf = v_fl

therefore,

Therefore, Luna will be running faster at the end of the race.

(b)

To calculate the time of completion we will use the first equation of motion:

FOR ANGELA:

FOR LUNA:

Hence, LUNA finishes the race first.