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3 years ago

9

A common design for a spotlight uses a lens and a mirror, combined with a gas-discharge lamp, to project a powerful parallel bea

m of light. Where are the lens and mirror positioned?

1 answer:

wel3 years ago

7 0

Answer:

Explanation:

For answer please see the image attached .

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Reuptake refers to the...

Arada [10]

Reuptake refers to the REABSORPTION of excess neurotransmitter molecules by a sending neuron (Option b).

Reuptake is the mechanism by which cells reabsorb chemical messengers produced and secreted by them. In nerve terminals, reuptake is used to reabsorb released neurotransmitters.

The reuptake mechanism is exploited in therapeutics for the development of target drugs and treatments.

Serotonin is a neurotransmitter that acts to stabilize different emotions such as mood, feelings of well-being, appetite and happiness.

For example, serotonin reuptake inhibitors which are capable of blocking the reuptake of serotonin to modulate serotonin brain levels have recently been developed.

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brainly.com/question/4439815?referrer=searchResults

4 0

2 years ago

Why does the cord of an electric heater not glow while the heating element does

Strike441 [17]

Answer: Why does the cord of an electric heater not glow while the heating element does? The heating element of the heater is made up of alloy which has very high resistance so when current flows through the heating element, it becomes too hot and glows red. But the resistance of cord which is usually of copper or aluminum is very low so it does not glow.

Explanation:

7 0

3 years ago

Compute the work performed when 32 pounds is lifted 10 feet.

Murljashka [212]

W = force * displacement
W = 32 pounds * 10 feet
Now you need to convert it to newton and meters
W = 142 N * 3.048 m = 434 J
(I approximated the conversions- I hope it helps)

7 0

3 years ago

A racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction with a speed of 26 m/s. The collision

Fudgin [204]

Answer:

The average acceleration of the ball during the collision with the wall is $a=2,800m/s^{2}$

Explanation:

<u>Known Data</u>

We will asume initial speed has a negative direction, $v_{i}=-30m/s$ , final speed has a positive direction, $v_{f}=26m/s$ , $\Delta t=20ms=0.020s$ and mass $m_{b}$ .

<u>Initial momentum</u>

$p_{i}=mv_{i}=(-30m/s)(m_{b})=-30m_{b}\ m/s$

<u>final momentum</u>

$p_{f}=mv_{f}=(26m/s)(m_{b})=26m_{b}\ m/s$

<u>Impulse</u>

$I=\Delta p=p_{f}-p_{i}=26m_{b}\ m/s-(-30m_{b}\ m/s)=56m_{b}\ m/s$

<u>Average Force</u>

$F=\frac{\Delta p}{\Delta t} =\frac{56m_{b}\ m/s}{0.020s} =2800m_{b} \ m/s^{2}$

<u>Average acceleration</u>

$F=ma$ , so $a=\frac{F}{m_{b}}$ .

Therefore, $a=\frac{2800m_{b} \ m/s^{2}}{m_{b}} =2800m/s^{2}$

8 0

3 years ago

two clear, colorless liquids are poured together. A bright yellow solid forms. What physical properties have changed?

jek_recluse [69]

Change in state(from liquid to solid) and change in colour I believe.

3 0

3 years ago