Respuesta :
Answer: He must drive at 58.8mi/hr
{3 significant figure}
Explanation: The original speed of the car to complete the journey normally is = 550mile/10hr
= 55mi/hr
The normal time to cover 120 mile with that speed is
t = distance/speed
= 120/55
=2hr, 0.18*60=11mins
= 2hr11mins.
But the driver found out he was 30mins behind at this distance, so he spent
2hr 11min +30min= 2hr41mins
For him to meet up the original schedule time 10hrs, he has
(10-2.41)hrs = 7hr19mins to cover the remaining distance of
{550-120}=430mile.
First, 7hr19mins= {7*(19/60)}hr
= {439/60}hr
Now let's find the speed at which the driver must move for him to cover for his initial delay
Speed= distance/time
= 430/{439/60}
This is same as writing
Speed = 430/439/60
Using the law of reciprocal,
Speed = (430*60)/439
= 25800/439
= 58.7699mi/hr
But we were asked to leave our answer in 3 significant figure. Therefore,
Speed = 58.8mi/hr
At a speed of 58.8mi/hr must he drive for the remainder of the trip to complete the trip in the usual amount of time.
What is velocity?
The change of displacement with respect to time is defined as speed. Speed is a scalar quantity. It is a time-based component. Its unit is m/sec.
The time it takes to go 120 miles at that speed in normal conditions is;
[tex]\rm t = \frac{d}{v} \\\\ t =\frac{120}{55} \\\\ t= 2 hour \ 11 minute[/tex]
However, the driver was 30 minutes behind schedule at this distance, so the time the has to spend is;
T== 2hr 11 min +30 min
T= 2hr 41 mins
He has to fulfill the initial planned moment of 10 hours. The time to cover the remaining distance;
T'=(10-2.41)
T' = 7hr19mins
The remaining distance will be ;
S={550-120}
S=430mile.
The speed is to be maintained the following distance on the time;
[tex]\rm V'=\frac{430}{(\frac{439}{60} )} \\\\V'=58.7699 \ miles / hour[/tex]
The speed must he drive for the remainder of the trip to complete the trip in the usual amount of time will be 58.5 mile/hr.
To learn more about the velocity refer to the link;
https://brainly.com/question/862972
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