Answer:
1. 600 watts
2. 35640 J
3. 55%
4. 20 J
5. The cost of running the fire is 8p.
Step-by-step explanation:
1. Energy = 36 000 J , t = 1 minute = 60 seconds
Power = 
= 
= 600 watts
2. Power = 
⇒ work done = Power × time
= 99 × 360
= 35640 J
3. Efficiency = (Output / Input) × 100
= 
× 100
= 55%
4. Work done = Force × distance
= 5 × 4
= 20 J
5. Given that 1 KWh cost 2p, Power = 4 KW and time = 4 hours.
Power =
Energy = Power × time
= 4 × 4
= 16 KWh
The cost of running the fire = 
= 8p
Answer:
x = 5
y = 4
Step-by-step explanation:
just substitute the value of one variable into the other
-x +y = -1
or y = -1 +x <-------- (i just added x to the right side)
now u know what y is equal to, just substitute that value into the first equation
2x - (-1+x) = 6 <-------- instead of y, i put the value of y from the 2 equation
NOW SOLVE FOR X!
2x +1 -x = 6
x + 1 = 6
x = 5
now solve for y since you have the value of x
y = -1 + x
or y = -1 + 5
y = 4
Answer:
< BCA = 70
Step-by-step explanation:
The complete central angle of a circle is 360 degrees. The given portion is 250 degrees.
What is left over? BOA = 360 - 250 = 110
Tangents always meet the radius at 90 degrees. Since there are two tangents <CAO = <BAO = 90 degrees.
So piecing it all together, the equation becomes
<BAO + CAO + BAO + ACB = 360
110 + 90 + 90 + <ACB = 360
290 + <ACB = 360
<ACB + 290 - 290 = 360 - 290
ACB = 70 degrees
