Answer
The answer for the first one I think is false.
The second one would be true i think. I hope i got it right and have a wonderful day
Answer: The change in length of the wire is= 8.613*10⁻⁷ m
Explanation:
The formula for Young's Modulus = Stress/ Strain
where x represents the change in length.
Rearranging the equation and making F/A the subject of the formula gives us
The use of area is not required as we have assumed the the force of Atmosphere is being applied on the crates which means
F/A = Atmospheric Pressure
1 atm = 101325 Pa
now solve:
101325 = (2.10*10¹¹ Pa) * (x/1.7)
Therefore, x= 8.613*10⁻⁷ m
<span>Velocity is the measurement rate of a certain
object as it moves towards other position over time. Therefore, it uses both
the factors of speed and time in order to calculate its actual measurement.
Velocity is calculated through the use of distance divided by speed; usually
meters divided by seconds.</span>
Well, that depends on how you look at it.
Efficiency =
<em>(amount of power that does what you want) / (total power supplied)</em>.
Power to charge battery . . . 1.31 watts
Power changed to heat . . . 3.52 watts
Total power supplied . . . . . . 4.83 watts
Using the cell-phone as a heater,
efficiency of the charger in supplying heat = 3.52 / 4.83 = <em>72.9 %</em> .
Using the cell-phone as cell-phone,
efficiency of the charger in charging the battery = 1.31 / 4.83 = <em>27.1 %</em> .
The charger is more efficient as a heater than it is as a battery charger.
Let Karen's forward speed be considered as positive.
Therefore, before the headband is tossed backward, the speed of the headband is
V = 9 m/s
The headband is tossed backward relative to Karen at a speed of 20 m/s. Therefore the speed of the headband relative to Karen is
U = -20 m/s
The absolute speed of the headband, relative to a stationary observer is
V - U
= 9 + (-20)
= - 11 m/s
Answer:
The stationary observes the headband traveling (in the opposite direction to Karen) at a speed of 11 m/s backward.