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scoray [572]
3 years ago
6

A bicyclist bikes the 90 mi to a city averaging a certain speed. The return trip is made at a speed that is 1 mph slower. Total

time for the round trip is 19 hr. Find the​ bicyclist's average speed on each part of the trip.
Physics
1 answer:
Lynna [10]3 years ago
5 0

Answer:

his speeds while going to city is 10 mph and while his round trip the speed will be 9 mph

Explanation:

Let say the speed of the bicycle while he moves towards the city is "v"

now the speed of the round trip must be smaller by 1 mph

so its speed for round trip will be

v_2 = v - 1

now we know that total time of the motion is 19 hr

so we will have

t_1 = \frac{90}{v}

t_2 = \frac{90}{v - 1}

so we will have

t_1 + t_2 = 19 hr

\frac{90}{v} + \frac{90}{v-1} = 19

90(2v - 1) = 19(v^2 - v)

19 v^2 - 199 v + 90 = 0

by solving above equation we have

v = 10 mph

so his speeds while going to city is 10 mph and while his round trip the speed will be 9 mph

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Answer:

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Explanation:

Let t be the time the accelerating car starts.

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the position of the constant velocity and accelerating vehicles are

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they pass when their distance is the same

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10t² = 40t + 80

0 = 10t² - 40t - 80

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t = (4±√(4² - 4(1)(-8))) / 2(1)

t = (4± 6.928) / 2  ignore the negative time as it has not occurred yet.

t = 5.464 s

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300 cm when rounded to the single significant digit of the question numerals.

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A projectile is fired horizontally from a height of 78.4 m at a speed of 300 m/sec. How far did it travel horizontally before hi
Mice21 [21]

Answer:

Explanation:

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Substitute into the fromula;

R = 300√2(78.4)/9.8

R = 300 √(16)

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Answer:

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fiasKO [112]
The formula for velocity vf = vi + at

First list your given information

2m/s Is your initial velocity (vi)
6m/s is you final velocity (vf)
2 seconds is your time (t)

Since you want the a for acceleration get a by itself

a = (vf-vi)/t

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Now units

the units for acceleration are m/sx^{2}

2m/sx^{2}
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