Answer:
01:20 (1 minute 20 seconds)
Explanation:
subtract the starting time from the stopping time to get the time used: 02:10 - 00:50 = 01:20
<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:
Accelerates in the same direction as the field
Explanation:
When a charge is immersed in an electric field, the charge experiences an electric force, whose magnitude is given by
F = qE
where q is the magnitude of the charge and E is the magnitude of the electric field.
The direction of the force depends on the sign of the charge. In particular,
- For a positive charge, F and E have the same direction
- For a negative charge, F and E have opposite directions
Therefore, a free positive charge will experience a force in the same direction as the field - therefore, it will accelerate in the same direction.
Explanation:
In science energy is simply defined as the ability to do work. Anything that causes work to be done must have expended some form of energy .
Energy is broadly categorized into two parts;
- Kinetic energy is the energy due to the motion of a body.
- Potential energy is the energy at rest in a body.
- Other forms of energy stems these two forms of energy.
- Thermal energy, mechanical energy are examples of kinetic energy.
- Chemical energy, gravitational energy are examples of potential energy.
- Energy is neither created nor destroyed but transformed from one form to another according to the law of conservation of energy.
learn more:
Kinetic energy brainly.com/question/4997571
#learnwithBrainly
Answer:
The total distance at 7 s is:
Explanation:
<u>Distance due to the force</u>
We can use second Newton's law to find the acceleration.
Now, using the kinematic equation we will find the distance during this interval of time. Let's recall that the initial velocity is zero.
In the second part of the motion, the object moves at a constant velocity, as long as there is no friction between the object and the floor.
First, we need to find the final velocity of the first interval
So the second distance will be:
Therefore, the total distance is:
I hope it helps you!
