Answer:

Step-by-step explanation:

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.
Answer:
x=-1, x=3, x=4
Step-by-step explanation:
1. Substitute 0 for f(x)
0=(x+1)(x-3)(x-4)
2. Set each set of parenthesis equal to 0
0=x+1, 0=x-3, 0=x-4
3. Solve for x
x=-1, x=3, x=4