Question

Carl is eating lunch at his favorite cafe when his friend Isaac calls and says he wants to meet him. Isaac is calling from a city 175 miles away, and wants to meet Carl somewhere between the two locations. Isaac says he will start driving right away, but Carl needs 35.0 min to finish his lunch before he can begin driving. Isaac plans to drive at 65.0 mph , and Carl plans to drive at 50.0 mph . Ignore acceleration and assume the highway forms a straight line. How long will Isaac be driving before he meets Carl?

Answer 1

Answer:

106.52 minutes

Explanation:

Given:

Initial distance between Carl and Isaac = 175 miles

speed of Isaac = 65 mph

Speed of Carl = 50 mph

Now, the Carl starts after 35 minutes, but the Isaac has already started so the distance covered by Isaac in 35 minutes will be

= $\frac{35}{60}\times65$

= 37.91 miles

Therefore,

the distance left between Isaac and Carl = 175 - 37.91 = 137.09 miles

Since Isaac and Carl are moving towards each other,

therefore the relative speed between the both = 65 + 50 = 115 mph

Hence, the time taken to meet = $\frac{137.09}{115}$

or

The time taken to meet = 1.192 hours

or

The time taken = 1.192 × 60 = 71.52 minutes

Therefore the total time Isaac have been travelling = 71.52 + 35

= 106.52 minutes