Answer:
B will take 1.034 times the time of A from Boston to Hartford.
Explanation:
Let the distance from Boston to Hartford be S.
Person A drives at a constant speed of 55 mph for the entire trip,
Time taken by person A

Person B drives at 65 mph for half the distance and then drives 45 mph for the second half of the distance.
Time taken by person B

Ratio of time of arrival of B to A

B will take 1.034 times the time of A from Boston to Hartford.
Let
upthrust = T
weight = W = mg
Air resistance = F
When balloon is descending, air resistance acts upwards (positive)
By Newton's first law, the net force on the balloon is zero, or
T+F-W=0......................(1)
Let w=weight of material dumped so that balloon now travels upwards at constant speed.
Air resistance acts against motion, namely downwards.
The Newton's equation now reads
T-F-(W-w)=0................(2)
Subtract (2) from (1)
T+F-W - (T-F-(W-w)) = 0
Solve for w
w=2F, or
the WEIGHT of material to be released equals twice the resistance of air.
Answer:
90.77%
its capacity utilization rate for the month is 90.77%
Explanation:
The capacity utilisation rate can be expressed mathematically as;
Capacity utilisation rate = capacity used/Best operating level × 100%
Given;
Total Number of production time = 205hours
Production output/capacity used = 21400 units
Best operation rate = 115units/hour
Best operation output for the month of July( at best operation level )
=115units/hour × 205 hours = 23575 units
Capacity utilisation rate = 21400/23575 × 100%
= 90.77%
<span>5.98 x 10^-2 ohms.
Resistance is defined as:
R = rl/A
where
R = resistance in ohms
r = resistivity (given as 1.59x10^-8)
l = length of wire.
A = Cross sectional area of wire.
So plugging into the formula, the known values, including the area of a circle being pi*r^2, gives:
R = 1.59x10^-8 * 3.00 / (pi * (5.04 x 10^-4)^2)
R = (4.77 x 10^-8) / (pi * 2.54016 x 10 ^-7)
R = (4.77 x 10^-8) / (7.98015 x 10^-7)
R = 5.98 x 10^-2 ohms
So that wire has a resistance of 5.98 x 10^-2 ohms.</span>