The average rate, in miles per hour, of the rail portion of the trip is; D: 75
<h3>How to calculate the average speed?</h3>
Since exactly 1/3 of the distance travelled was by rail, then we can say that;
(1/3) * (90) = 30 miles
We are told that part of the trip took 1/5 of the travel time. Thus;
Time it takes to travel that distance is:
(1/5) * (2) = 2/5 of an hour
Average rate is;
30/(2/5) = 150/2 = 75 mph
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We are given a concave spherical mirror with the following dimensions:
Radius = 60 cm; D o = 30 cm
Height = 6 cm; h o = 6 cm
First, we need to know the focal length, f, of the object (this should be given). Then we can use the following formulas for calculation:
Assume f = 10 cm
1/ f = 1 /d o + 1 / d i
1 / 10 = 1 / 30 + 1 / d i
d i = 15 cm
Then, calculate for h i:
h i / h o = - d i / d o
h i / 6 = - 15 / 30
h i = - 3 cm
Therefore, the distance of the object from the mirror is 3 centimeters. The negative sign means it is "inverted".
Dont u think their should be more points for 4 hard questions
a statistic question is with multiple answers
