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3 years ago

At what distance must a star be to have its apparent magnitude equal to its absolute magnitude?

1 answer:

6 0

10 parsecs<span>Another way to look at this is that the apparent magnitude (brightness from true distance) is brighter than the absolute magnitude (brightness from 10 parsecsaway). So Ross 128 must be closer than 10 parsecs, making star look brighter than it "really" is.</span>

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____ have more energy than ____. A. Radio waves; microwaves B. Ultraviolet rays; X-Rays C. Gamma rays; infrared rays D. Radio wa

Aloiza [94]

C. Gamma rays have more energy than infrared rays

6 0

3 years ago

A uniform plank of length 5.0 m and weight 225 N rests horizontally on two supports, with 1.1 m of the plank hanging over the ri

lawyer [7]

Answer:

x = 0.6034 m

Explanation:

Given

L = 5 m

Wplank = 225 N

Wman = 522 N

d = 1.1 m

x = ?

We have to take sum of torques about the right support point. If the board is just about to tip, the normal force from the left support will be going to zero. So the only torques come from the weight of the plank and the weight of the man.

∑τ = 0 ⇒ τ₁ + τ₂ = 0

Torque come from the weight of the plank = τ₁

Torque come from the weight of the man = τ₂

⇒ τ₁ = + (5 - 1.1)*(225/5)*((5 - 1.1)/2) - (1.1)*(225/5)*((1.1)/2) = 315 N-m (counterclockwise)

⇒ τ₂ = Wman*x = 522 N*x (clockwise)

then

τ₁ + τ₂ = (315 N-m) + (- 522 N*x) = 0

⇒ x = 0.6034 m

7 0

3 years ago

Two airplanes leave an airport at the same time. The velocity of the first airplane is 730 m/h at a heading of 44.3 ◦ . The velo

Goshia [24]

Answer:

So airplane will be 1324.9453 m apart after 2.9 hour

Explanation:

So if we draw the vectors of a 2d graph we see that the difference in angles is = 83 - 44.3 = $83-44.3=38.7^{\circ}$

Distance traveled by first plane = 730×2.9 = 2117 m

And distance traveled by second plane = 590×2.9 = 1711 m

We represent these distances as two sides of the triangle, and the distance between the planes as the side opposing the angle 38.7.

Using the law of cosine, $d^2$ representing the distance between the planes, we see that:

$d^2=2117^2 + 1711^2 -2\times (2117)\times (1711)cos(38.7)=1755480.2482$

d = 1324.9453 m

4 0

3 years ago

Amy crashed her bike into the fence. She was thrown over it onto the lawn. Which Newton law applies

BlackZzzverrR [31]

Answer:

Newton's First Law of Motion applies here.

Explanation:

Before crashing into the fence, Amy was moving at a certain speed on her bike. As, she crashed her bike into the fence, the collision stopped the bike suddenly. But, Amy had the same speed due to inertia of her body. Due tot his speed Amy did not stop and she was thrown over the fence onto the lawn. So, the force of inertia of Amy's body caused her to be overthrown in this case. We study about inertia in Newton's First Law of Motion, which is also known as Law of Inertia.

<u>Newton's First Law of Motion applies here.</u>

7 0

2 years ago

You and a friend are studying late at night. There are three 110 W light bulbs and a radio with an internal resistance of 56.0 Ω

Sliva [168]

Answer:

The total electrical power we are using is: 1316 W.

Explanation:

Using the ohm´s law $V=I*R$ and the formula for calculate the electrical power, we can find the total electrical power that we are using. First we need to find each electrical power that is using every single component, so the radio power is: $I=\frac{V}{R}=\frac{110 (v)}{56(ohms)}=1.96(A)$ , so the radio power is: $P=I*V=1.96(A)*110(v)=216(W)$ , then we find the pop-corn machine power as: $P=I*V=7(A)*110(v)=770(W)$ and finally there are three light bulbs of 110(W) so: P=3*110(W)=330(W) and the total electrical power is the adding up every single power so that: P=330(W)+770(W)+216(W)=1316(W).

8 0

3 years ago