Using the formula A squared plus B squared equals C squared, we can find the solution by substituting 5 for A and 12 for B.
By squaring 5, we get 25, and by squaring 12, we get 144. Adding these, we get 169. The square root of this is 13.
Answer:
a) v(2) = 2m/s, v(3) = -2m/s
b) speed at t = 2s is 2m/s
speed at t = 3s is 2m/s
c) 0 m/s
Explanation:
We can take the derivative of x(t) to find the equation of velocity
v(t) = x'(t) = 10 - 4t
(a) v(2) = 10 - 4*2 = 10 - 8 = 2 m/s
v(3) = 10 - 4*3 = 10 - 12 = -2 m/s
(b) The speed would be the same as velocity without the direction
speed at t = 2s is 2m/s
speed at t = 3s is 2m/s
(c) The average velocity between t = 2s and t = 3s is distance it travels over period of time
<span>The first thing to do here is to figure out how many joules of energy would be produced by your lightbulb in one hour.
As you can see, the conversion factor to use here is
#"1 W" = "1 J"/"1 s"#
This is basically a reminder of the fact that the watt, a unit of power, is defined as an energy of one joule delivered in one second.
Since one hour is known to have #60# minutes, i.e. #60 xx "60 s"#, you will have
#60 xx 60 color(red)(cancel(color(black)("s"))) * "140 J"/(1color(red)(cancel(color(black)("s")))) = "504000 J" = "504 kJ"#
Your next step here will be to use the enthalpy of vaporization of water to figure out how many grams of water would be evaporated by that much heat.
#DeltaH_"vap" = "44.66 kJ mol"^(-1)#
Convert this to kilojoules per gram by using water's molar mass
#44.66 "kJ"/color(red)(cancel(color(black)("mol"))) * (1color(red)(cancel(color(black)("mole H"_2"O"))))/("18.015 g") = "2.479 kJ g"^(-1)#
This means that the mass of water that can be evaporated by #"504 kJ"# of heat will be
#504color(red)(cancel(color(black)("kJ"))) * ("1 g H"_2"O")/(2.497color(red)(cancel(color(black)("kJ")))) = "201.8 g"#
Now, assuming that the sweat is pure water, you can approximate its density to be equal to #"1.0 g mL"^(-1)#. This means that the volume of water that can be evaporated will be
#201.8 color(red)(cancel(color(black)("g"))) * "1 mL"/(1.0color(red)(cancel(color(black)("g")))) = color(green)(bar(ul(|color(white)(a/a)color(black)(2.0 * 10^2 "mL")color(white)(a/a)|)))#
The answer is rounded to two</span>
Answer:
the elements are made up of only one kind of atom, the compounds consist of two or more elements that are chemically combined, and the mixtures are physical combination of two or more substances