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2 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:

wel2 years ago

7 0

Answer:

Explanation:

For answer please see the image attached .

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A 285-mL flask contains pure helium at a pressure of 750 torr . A second flask with a volume of 455 mL contains pure argon at a

zaharov [31]

Answer:

$P_{He}^|=288.85torr$

Explanation:

Given data

$P_{He}=750 torr\\V_{He}=285mL\\P_{Ar}=732 torr\\V_{Ar}=455 mL$

Required

Partial pressure of helium

Solution

First calculate the total volume of gas mixture once the stopcock is opened

So

$V_{total}=V_{He}+V_{Ar}\\V_{total}=285mL+455mL\\V_{total}=740mL$

As temperature remains constant,by Boyle's Law we calculate the partial pressure of the helium gas

So

$P_{He}V_{He}=P_{He}^|V_{total}\\P_{He}^|=\frac{P_{He}V_{He}}{V_{total}}\\P_{He}^|=\frac{750torr*285mL}{740mL}\\ P_{He}^|=288.85torr$

5 0

3 years ago

Read 2 more answers

Sam is observing the velocity of a car at different times. After two hours, the velocity of the car is 54 km/h. After four hours

MariettaO [177]

With that information you can only suppose a uniformly accelerated motion. This is, acceleration is constant.

Then, acceleration = change in velocity / change in time = (58 -54)km/h / 2 h = 4km/h / 2 h = 2 km/h^2

Then the equation for velocity, V is

V = Vo + a*t = Vo + 2 (km/h^2) * t = Vo + 2t

Vo is the initial velocity, which you can find using V = 54km/h and t = -2

Vo = V after 2 hours - a*(2hours) = 54km/h - 2(km/h^2)*2h = 54km/k - 4km/h = 50km/h

Then, the equation is: V = 50 km/h + 2t

Valid for constant acceleration.

5 0

2 years ago

What is the mass of a dog running at a speed of 5 m/s and a momentum of 120.5 kgm/s?

viktelen [127]

Given:

Momentum of the dog (p) = 120.5 kg m/s

Speed of the dog (v) = 5 m/s

To Find:

Mass of the dog (m)

Concept/Theory:

$\underline{\underline{ \bf{\Large{Momentum}}}}$

It is defined as the quantity of motion contained in a body.
It is measured as the product of mass of the body and it's speed.
It is represented by p.
It's SI unit is kg m/s
Mathematical Representation/Equation of Momentum: $\boxed{ \bf{p = mv}}$

Answer:

By using equation of momentum, we get:

$\rm \longrightarrow m = \dfrac{p}{v} \\ \\ \rm \longrightarrow m = \dfrac{120.5}{5} \\ \\ \rm \longrightarrow m = 24.1 \: kg$

$\therefore$ Mass of the dog (m) = 24.1 kg

6 0

2 years ago

Will give brainliest to right answer!

viva [34]

The correct answer is D.

8 0

3 years ago

Choose all facts that increase the orbital velocity of a vessel around planet B. Bigger mass of planet B smaller mass of planet

telo118 [61]

Answer:

- Bigger mass of planet B

- orbiting closer to planet B

Explanation:

The orbital velocity of the vessel around the planet can be found by equalizing the force of gravity between the vessel and the planet and the centripetal force:

$G\frac{mM}{r^2}=m\frac{v^2}{r}$

where

G is the gravitational constant

m is the mass of the vessel

M is the mass of the planet

r is the distance between the vessel and the centre of the planet

v is the orbital velocity of the vessel

Re-arranging the formula, we find an expression for v:

$v=\sqrt{\frac{GM}{r}}$

We see that:

- the bigger the mass of the planet, M, the bigger the velocity

- the bigger the distance between the vessel and the planet, r, the smaller the velocity

So, the correct choices that increase the orbital velocity are:

- Bigger mass of planet B

- orbiting closer to planet B

6 0

3 years ago