Answer:
4 ohms
Step-by-step explanation:
The question is "In two minutes a current of 5 amps develops 1,200 heat units in a wire of 8 ohms resistance. What resistance does a similar wire have, which develops 6,000 heat units with a current of 10 amps in 5 minutes?"
Current, I₁ = 5 A
Heat, Q₁ = 1200 units
Resistance, R₁ = 8 ohms
Time, t₁ = 2 min = 120 s
New heat, Q₂ = 6000 units
Current, I₂ = 10 A
New time, t₂ = 5 min = 300 s
We need to find the new resistance.
Heat developed is given by :
So, the new resistance is 4 ohms.
Ok, so I used the equation Y2 (4) - Y1 (-10) over X2 (2) -X1 (-5).
4 - -10 is 14 since if a minus sign is before a negative number, it becomes positive.
Same goes for 2 - -5. It is 7 since the minus sign is before the negative number. Final answer is 14/7 which can be simpflied to 2/1 since 14 divided by 7 =2. So the distance is 14\7, or 2\1.
Steps:
1) Draw the circle and mark the center (A) and the given point (B)
2) Draw a line that passes through the center (A) and the given poiint (B).
3) Draw a perpendicular line to the segment AB.
The last line drawn is tangent to the circle at the given point.
Answer:
<em>24 children</em>
Step-by-step explanation:
If the length of time, y hours, it takes to put a jigsaw puzzle together is inversely proportional to the number of children, x, this is represented as;
k is the constant of proportionality
If it takes 16 children 6 hours to put the jigsaw puzzle together, this means at x = 16, y = 6
Substitute:
6 = k/16
k = 6*16
k = 96
W are to find number of children needed to put the same jigsaw puzzle together in 4 hours, this is done by substituting k = 96 and y = 4 into the expression y = k/x
y = 96/4
y = 24
<em>Hence it will take 24 children to put the same jigsaw puzzle together in 4 hours</em>
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