Answer:
h2 = 0.092m
Explanation:
From a balance of energy from point A to point B, we get speed before the collision:
Solving for Vb:
Since the collision is elastic, we now that velocity of bead 1 after the collision is given by:
Now, by doing another balance of energy from the instant after the collision, to the point where bead 1 stops, we get the distance it rises:
Solving for h2:
h2 = 0.092m
We will put the number of trips in the first column, the miles driven in the second column and gallons of fuel used in the third column.
8 7,680 1,010
7 9,940 1,330
12 14,640 1,790
12 13,920 2,050
Gravitational attraction / field strength increases when closer; A light dependent resistor (LDR) can be used as a sensor to detect light intensity.
Answer:
This is an incomplete question. The complete question is --
An individual white LED (light-emitting diode) has an efficiency of 20% and uses 1.0 W of electric power.
How many LEDs must be combined into one light source to give a total of 3.8W of visible-light output (comparable to the light output of a 100W incandescent bulb)?
And the answer is --
19 LEDs
Explanation:
The full form of LED is Light emitting diode.
It is given that the efficiency of the LED bulb is 20 %
1 LED uses power = 1 W
So the output power of 1 LED = 0.2 W
We need to find the power required to give a 3.8 W light.
Power required for 3.8 W = Number of LEDs required = (total required power / power required for 1 LED )
= 3.8 / 0.2
= 19
Therefore, the number of LEDs required is 19.
