Which of the following explains why international travelers need to use special adapters when plugging a device designed to oper
ate in the U.S. into a wall outlet in Europe? The increased voltage causes the device's resistance to increase, and the device won't work.
The increased voltage causes the device's resistance to decrease, and the device will over-heat.
The increased voltage causes an increase in power usage, and the device will over-heat.
The increased voltage causes a decrease in power usage, and the device won't work.
The answer is: The increased voltage causes an increase in power usage, and the device will over-heat.
Explanation:
First, we must consider the variables of the electrical system that will allow us to respond. In this case, power, current and voltage, which are related by
Where P=Power, V=Voltage, I=Current.
In the equation it can be observed that power is directly proportional to the system voltage. Thus, if the voltage increases as in this case, the power will also increase, which overheats the device and can cause damage to it.
Approximately (assuming that , the ball was launched from ground level, and that the drag on the ball is negligible.)
Explanation:
Let denote the velocity at which the ball was thrown upward.
If the drag (air friction) on the ball is negligible, the ball would land with a velocity of exactly . The velocity of the ball would be changed from to (such that ) within .
Also because the drag on the ball is negligible, the acceleration of the ball would be . Thus:
.
Since :
.
.
The ball reaches maximum height when its velocity is . Apply the SUVAT equation to find the displacement between the original position (ground level, where ) and the max-height position of the ball (where .)
<span>A. Any object of any mass pulls other objects toward it anywhere in the universe. The earth had a force that attracted the apple and the apple had the same force that pulled the earth toward it.</span>