Laptop computers are made with batteries, but they must also be plugged into outlets to charge the batteries. which is true regarding laptops?

1.they run only on alternating current.
2.they run only on direct current.
3.they can run on either direct or alternating current.
4.they do not run on direct or alternating current.

3. They can run on either direct or alternating current.

Computers and Technology

Physics

Electricity

Manufacturers built laptops and their battery components on DC currents, meaning it is a one-way electricity path.

We also know that our wall outlets and electricity from the power lines and energy companies are AC, meaning they switch paths and alternate in their current.

Since we need to plug in our laptops in order to charge them, we use a power brick. Power bricks convert the AC current flowing into the charger into DC current and sends it to your laptop battery.

Misconception:

Laptops only run on DC current. We can say, however, that laptops can run on both DC and AC currents, but remember that the power brick/charger is the component that is converting the currents.

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

6 times more