Alan leaves Los Angeles at 8:00 a.m. to drive to San Francisco, 400 {\rm mi} away. He travels at a steady 47.0 mph. Beth leaves Los Angeles at 9:00 a.m. and drives a steady 55.0 mph. Who gets to San Francisco first? How long does the first to arrive have to wait for the second?

Respuesta :

Complete question is;

Alan leaves Los Angeles at 8:AM to drive to San Francisco, 400 mi away. He travels at a steady 47 mph. Beth leaves Los Angeles at 9:00 AM and drives a steady 55.0 mph.

a. Who gets to San Francisco first?

b. How long does the first to arrive have to wait for the second?

Answer:

A) Beth will get there first

B) Beth will have to wait for 15 minutes for alan

Explanation:

We are given;

Distance between Los Angeles and San Francisco;d = 400 mi

Alan's velocity;v_a = 47 mph

Beth's velocity;v_b = 55 mph

we know that time is given by;

Time = distance/velocity

Time required for alan;

t_a = 400/47

t_a = 8.5106 hours = 8 hours 31 minutes

Time required for Beth;

t_b = 400/55

t_b = 7.2727 hours = 7 hours 16 minutes

So Alan will reach there at;

8:00 a.m + 8 hours 31 minutes = 4:31 p.m

Beth will reach there at;

9:00 a.m + 7 hours 16 minutes = 4:16 pm

Thus, beth will arrive 4:31 pm - 4:16pm = 15 minutes before alan

A) Beth will get there first

B) Beth will have to wait for 15 minutes for alan

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