<span>It takes heat to make something evaporate, so it takes heat from your arm. Alcohol easily evaporates at room temperature, so it feels cool. This is also why you feel cool when getting out of the pool. The water on your skin evaporates.
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Answer:
The correct answer is the third option: The kinetic energy of the water molecules decreases.
Explanation:
Temperature is, in depth, a statistical value; kind of an average of the particles movement in any physical system (such as a glass filled with water). Kinetic energy, for sure, is the energy resulting from movement (technically depending on mass and velocity of a system; in other words, the faster something moves, the greater its kinetic energy.
Since temperature is related to the total average random movement in a system, and so is the kinetic energy (related to movement through velocity), as the thermometer measures <u>less temperature</u>, that would mean that the particles (in this case: water particles) are <u>moving slowly</u>, so that: the slower something moves, the lower its kinetic energy.
<u>In summary:</u> temperature tells about how fast are moving and colliding the particles within a system, and since it is <em>directly proportional</em> to the amount of movement, it can be related (also <em>directly proportional</em>) to the kinectic energy.
Explanation:
Question 1
1.The wires are made of conducting materials e.g copper
2. A light bulb is made of filament material e.g tungsten with gases enclosed in a glass material
3.The lens is made of transparent glass material
4 The reflector is made of plastic with silver lining
5. The exterior casing of most flash lights are made of plastic
Question 2.
1.Copper is used to conduct electric current from the battery to the bulb
2.The tungsten filament ignite the gases and causes it to glow
3. The lens covers the lamp on your flashlight so that the glass on the lamp
/bulbs does not get broken.
4.The reflector redirects the light rays from the lamp, creating a steady beam of light, which is the light you see emitting from the flashlight.
5. The exterior cases houses the entire assembly and makes the flash light handy for use
Answer: The magnetic field of a bar magnet is strongest at either pole of the magnet. It is equally strong at the north pole compared with the south pole. The force is weaker in the middle of the magnet and halfway between the pole and the center. So it would be D.
Answer:
v = 2.45 m/s
Explanation:
first we find the time taken during this motion by considering the vertical motion only and applying second equation of motion:
h = Vi t + (1/2)gt²
where,
h = height of cliff = 15 m
Vi = Initial Vertical Velocity = 0 m/s
t = time taken = ?
g = 9.8 m/s²
Therefore,
15 m = (0 m/s) t + (1/2)(9.8 m/s²)t²
t² = (15 m)/(4.9 m/s²)
t = √3.06 s²
t = 1.75 s
Now, we consider the horizontal motion. Since, we neglect air friction effects. Therefore, the horizontal motion has uniform velocity. Therefore,
s = vt
where,
s = horizontal distance covered = 4.3 m
v = original horizontal velocity = ?
Therefore,
4.3 m = v(1.75 s)
v = 4.3 m/1.75 s
<u>v = 2.45 m/s</u>
