3 the radius of both bases are the sams
You figure out how long it would take a car traveling at 25 mph
to cover 360 ft. Any driver who does it in less time is speeding.
(25 mi/hr) · (5,280 ft/mile) · (1 hr / 3,600 sec)
= (25 · 5280 / 3600) ft/sec = (36 and 2/3) feet per second.
To cover 360 ft at 25 mph, it would take
360 ft / (36 and 2/3 ft/sec) = 9.82 seconds .
Anybody who covers the 360 feet in less than 9.82 seconds
is moving faster than 25 mph.
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If you're interested, here's how to do it in the other direction:
Let's say a car covers the 360 feet in ' S ' seconds.
What's the speed of the car ?
(360 ft / S sec) · (1 mile / 5280 feet) · (3600 sec/hour)
= (360 · 3600) / (S · 5280) mile/hour
= 245.5 / S miles per hour .
The teacher timed one car crossing both strips in 7.0 seconds.
How fast was that car traveling ?
245.5 / 7.0 = 35.1 miles per hour
Another teacher timed another car that took 9.82 seconds to cross
both strips. How fast was this car traveling ?
245.5 / 9.82 = 25 miles per hour
Answer:
the answer is D 8.8
Step-by-step explanation:
Answer is 36.
First use the negative exponent rule. When a number is put to the negative power it becomes a fraction
4/3^2
Now 3 to the second power is 9
4/1/9 (4 over 1/9)
Now multiply 4 x 9 (dividing by 1/9 is the same as multiplying by 9)
4 x 9= 36
To solve this problem, let us first assign variables. Let
us say that:
A = runner
B = cyclist
d = distance
v = velocity
time = t
The time in which the cyclist overtakes the runner is the
time wherein the distance of the two is the same, that is:
dA = dB
We know that the formula for calculating distance is:
d = v t
therefore,
vA tA = vB tB
Further, we know that tA = tB + 2, therefore:
vA (tB + 2) = vB tB
4 (tB + 2) = 14 tB
4 tB + 8 = 14 tB
10 tB = 8
tB = 0.8 hours = 48 min
Therefore the cyclist overtakes the runner after 0.8
hours or 48 minutes.
