Answer:
134.75935 seconds
Explanation:
m = Amount of water = 240 mL
c = Specific heat of water = 4.2 J/mL °C
= Change in temperature =
t = Time taken
P = Power = 1100 W
E = Pt
Efficiency = 51 %
So, Energy = 0.51Pt
As energy is conserved
Q = 0
The it takes to raise the temperature is 134.75935 seconds
Answer:
(5/3,-5/6) or (1.67, -0.83)
Explanation:
the center if there are 4 bricks is the point 0,0 or intersection of the two arrow.
if we remove one on the top left, with the center of the mass in (-5,2.5), the the new coordinates of the center of mass can be found like this
x = A1 x1 - A2 x2 / (A1 - A2)
x = new coordinate of the system
A1 is the Area of 4 bricks = 20 x 10 = 200 cm²
A2 is the Area of 1 brick we remove, the top left = 10 x 5 = 50 cm²
x1 = the x coordinate of the center of mass when there are 4 bricks, x = 0
x2 = the x coordinate of the center of mass of the remove brick, x = -5
x = (200 . 0) - (50 . (-5))/(200 - 50)
x = - (-250) / 150
x = 250/150 = 5/3 = 1.67 cm
we can find the value y of the new coordinate, the same way we find x
y = A1 y1 - A2 y2 / (A1 - A2)
y = (200 . 0) - (50 . 2.5) / (200-50)
y = - 125/150
y = -5/6 = -0.83 cm
