What could we call the grocery store? A. Linear motion B. Reference point C. Rotary

While on a sailboat at anchor, you notice that 15 waves pass its bow every minute. The waves have a speed of 6.0 m/s . Part A Wh

Alchen [17]

Answer:

Distance between two adjacent wave crests = 24m

Explanation:

Distance= speed × time

Distance traveled by waves in 60 seconds (15 crests)= 15 × distance

15 × distance = 6,0 (meters/second) × 60 seconds

distance = (360 meters) / 15 = 24 meters (between two adyacent waves)

8 0

2 years ago

Calculate the moment of Inertia for a ring with a mass 0.715 kg, an inner radius of 10.7 cm and an outer radius of 12.7 cm.

lisov135 [29]

Using formula:
I=(1/2)*M*(R^2+r^2)

I=0.5*0.715kg*[(12.7cm)^2+(10.7cm)^2] 

I=98.6 kg*cm^2

7 0

2 years ago

NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large, low- mass sail and the ene

RUDIKE [14]

Answer:

d. The sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.

Explanation:

Let us take the momentum of a photon unit as u

we know that the rate of change of momentum is proportional to the force exerted.

For a absorbing surface, the photon is absorbed, therefore the final momentum is zero. From this we can say that

F = (u - 0)/t = u/t

for a unit time, the force is proportional to the momentum of the wave due to its energy density. Therefore,

F = u

For a reflecting surface, the momentum of the wave strikes the sail and changes direction. Since we know that the speed of light does not change, then the force is proportional to

F = (u - (-u))/t = 2u/t

just as the we did above, it becomes

F = 2u.

From this we can see that the force for a reflective sail is twice of that for an absorbing sail, and we know that the pressure is proportional to the force for a given area. From these, we conclude that the sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.

3 0

2 years ago

The near point of an eye is 48.5 cm. A corrective lens is to be used to allow this eye to focus clearly on objects at the distan

Masteriza [31]

Answer:

The focal length of the lens should be -51.5 cm (a concave lens).

Explanation:

The purpose of the lens is to make objects at 48.5 cm appear at the healthy near point. The healthy near point is 25.0 cm.

We use the lens formula

$\dfrac{1}{f} = \dfrac{1}{u} + \dfrac{1}{v}$

where f = focal length, u = object distance and v = image distance.

In this case, u = 48.5 cm and v = -25.0 cm.

v is negative because the image is virtual an not real. (Here, we are using the real-is-positive sign convention)

$\dfrac{1}{f} = \dfrac{1}{48.5} + \dfrac{1}{-25.0} = -\dfrac{23.5}{1212.5}$

$f = -51.5$

The negative sign indicates the lens is concave.

3 0

2 years ago

Scientists _____. Select all that apply.

Annette [7]

The true answer is the choice A
Scientists can predict volcanic eruptions as long as adequate resources are available.Volcanic eruptions are one of the earthly activities which can be predicted by means of adequate resources (warming of the earth's crust, appearance of volcanic lava etc...). By contrast, earthquakes is a dangerous natural disaster that scientists cannot be predicted or mastering the time where it occurs.

5 0

3 years ago