<u>#2</u>
Use the formula ... Kinetic energy = (1/2) x (mass) x (speed)²
<u>#3 - a).</u>
sun => energy travels as electromagnetic waves => reaches Earth as
heat & light energy.
sun => absorbed in plants => eaten by animals => animals die =>
decay into oil in millions of years => we burn the oil to get the energy.
<u>#3 - b).</u>
food I ate for lunch => metabolized into glucose by my body
=> some of it burned in my muscles to generate energy for immediate needs
=> the rest of it stored as fat for future needs.
<u>#3 - c).</u>
flower pot rolls off the ledge => gravity does work on it all the way down,
producing the kinetic energy it has when it hits the floor.
<u>#3 - d).</u>
oil or natural gas is burned, releasing heat energy => energy is used
to generate electricity => electricity flows through cables from the
power generating plant to your home => hot plate plugged into the
wall => turns electrical energy back into heat energy => heat energy
is conducted into the bottom of the beaker, flows through the glass
to the inside surface => heat energy is conducted from the inside of
the glass to the water, which gets hotter as it absorbs more energy.
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<u>Note:</u>
#1 on the sheet is wrong.
"Work = force x distance" that's correct
But 25-kg is the <em>mass</em> of the ball, <em>not </em>the gravitational <em>force </em>on it.
The force on it is (mass) x (gravity), called its "weight".
That's (25-kg) x (9.8 m/s²) = 245 kg-m/s² = 245 newtons .
Answer: the same as Lily's
Explanation:
Angular velocity has to do with the speed at which an object will be able to rotate. We are informed that Bob and Lily are riding on a merry-go-round.
Since we are further told that Bob rides on a horse near the outer edge of the circular platform, and Lily rides on a horse near the center of the circular platform and that he merry-go-round is rotating at a constant angular speed.
Based on the above analysis, Bob's angular speed will be thesame as that of Lily.
Answer:
25 meters per second
Explanation:
2 halves so you find the average of the two by adding 20+30=50 then dividing it by number of halves, this is 2.
50/2=25
Answer:
Both choices B and C are valid
Explanation:
Sound wave are Mechanical wave. Air (or viscus fluid) is the medium of propagation. Sound is produced by the back and forth vibration of the object. Consider the vibration of object is from left to right then this back and forth vibrations of object displaces the molecules of the medium both rightward and leftward (to and fro) to the direction of the energy transport forming compression and rarefaction. This shows that the motion of the molecules of the medium is both parallel (and anti-parallel) to the direction of the sound wave propagation.
