Answer: A.) y = log3(x) - 1
Step-by-step explanation: On edge, you're welcome !
The potential energy, E, of the penny is given by E=mgh. The energy, Q, required to raise the temperature of an object by an amount ΔT is given by Q=mcΔT. We can equate these two to get the result but we must use proper units and include the 60%:
(0.6)mgh=mcΔT
We see we can divide out the mass from each side
0.6gh=cΔT, then 0.6gh/c=ΔT
(0.6)9.81(m/s²)50m/385(J/kg°C) = 0.7644°C
since this is the change in temperature and it started at 25°C we get
T=25.7644°C
As you can see the result does not depend on mass. The more massive the copper object the more potential energy it will have to contribute to the heat energy, but the more stuff there will be to heat up, and the effect is that the mass cancels.
The answer would be 3. 3 is the largest factor that both numbers have in common.
Let a and b be the respective rates in bricks per minute for Alex and Bob separately.
Alex lays 4 bricks per minute more than Bob
a = b + 4
Working together, their rates scale by 3/4 and they achieve 15 bricks per minutes.
(3/4)(a + b) = 15
Two equations, two unknowns, we solve:
b = a - 4
(3/4)(a + a - 4) = 15
2a - 4 = (4/3) 15 = 20
2a = 24
a = 12
b = a - 4 = 8
Answer: Alex alone does 12 bricks per minute, Bob alone 8 bricks per minute
Check: a=b+4, good
(3/4)(12 +8)=(3/4)(20)=15, good
Area of a rectangle formula: A=LW
substitute the values in:
122.12=L(8.7)
Solve for L. Divide by 8.7 to isolate L.
L≈14.04 feet
