<span>The question is what do all types of waves transfer. Waves, both mechanical and electromagnetic are disturbances that transfer energy without transporting matter. It doesnt matter wether they are propagating trough a medium or trough vacuum. Therefore the correct answer is A. energy.</span>
Answer:
a)54L/min
b)0.845
Explanation:
a) A x V=
where suffix 1,2,3 refers to the three pipes.
=27L/min+16L/min+11 L/min
=54L/min
b) A x V=54L/min => 
x v
d= 2 cm
x v = 54
v= 
x 
-> 
x 
=27L/min => 
x 
= 1.3cm
x = 27
= x 
Next is to find the ratio of speed i.e 
x / x => 
= 0.845
Using the given equation you get:
E = 1.99x10^-25 / 9.0x10^-6
Divide 1.99 by 9.0: 1.99/9.0 = 0.22
For the scientific notation, when dividing subtract the two exponents:
25 -6 = 19
So you now have 0.22 x 10^-19
Now you need to change the 0.22 to be in scientific notation form:
2.2 x 10^-20
The answer is B.
The bimetallic strip in a fire alarm is made of two metals with different expansion rates bonded together to form one piece of metal. Typically, the low-expansion side is made of a nickel-iron alloy called Invar, while the high-expansion side is an alloy of copper or nickel. The strip is electrically energized with a low-voltage current. When the strip is heated by fire, the high-expansion side bends the strip toward an electrical contact. When the strip touches that contact, it completes a circuit that triggers the alarm to sound. The width of the gap between the contacts determines the temperature that will set off the alarm.
