Which experiment proved light was a wave?

Consult interactive solution 2.22 before beginning this problem. a car is traveling along a straight road at a velocity of +30.0

Inessa05 [86]

Let $a_1$ be the average acceleration over the first 2.46 seconds, and $a_2$ the average acceleration over the next 6.79 seconds.

At the start, the car has velocity 30.0 m/s, and at the end of the total 9.25 second interval it has velocity 15.2 m/s. Let $v$ be the velocity of the car after the first 2.46 seconds.

By definition of average acceleration, we have

$a_1=\dfrac{v-30.0\,\frac{\mathrm m}{\mathrm s}}{2.46\,\mathrm s}$

$a_2=\dfrac{15.2\,\frac{\mathrm m}{\mathrm s}-v}{6.79\,\mathrm s}$

and we're also told that

$\dfrac{a_1}{a_2}=1.66$

(or possibly the other way around; I'll consider that case later). We can solve for $a_1$ in the ratio equation and substitute it into the first average acceleration equation, and in turn we end up with an equation independent of the accelerations:

$1.66a_2=\dfrac{v-30.0\,\frac{\mathrm m}{\mathrm s}}{2.46\,\mathrm s}$

$\implies1.66\left(\dfrac{15.2\,\frac{\mathrm m}{\mathrm s}-v}{6.79\,\mathrm s}\right)=\dfrac{v-30.0\,\frac{\mathrm m}{\mathrm s}}{2.46\,\mathrm s}$

Now we can solve for $v$ . We find that

$v=20.8\,\dfrac{\mathrm m}{\mathrm s}$

In the case that the ratio of accelerations is actually

$\dfrac{a_2}{a_1}=1.66$

we would instead have

$\dfrac{15.2\,\frac{\mathrm m}{\mathrm s}-v}{6.79\,\mathrm s}=1.66\left(\dfrac{v-30.0\,\frac{\mathrm m}{\mathrm s}}{2.46\,\mathrm s}\right)$

in which case we would get a velocity of

$v=24.4\,\dfrac{\mathrm m}{\mathrm s}$

6 0

3 years ago

Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. After chatting for a few min

Alex

Average speed = (total distance covered) / (time to cover the distance)

Total distance = (80m) + (125m) + (45m) = 250 meters

Overall time = 10 minutes

Average speed = (250 meters) / (10 minutes)

<em>Average speed = 25 meters/minute </em>

Since we're only looking for average speed and not velocity, we don't care about any of the directions, and we don't need to calculate Mary's displacement.

7 0

3 years ago

One day, Pinki was ironing the clothes in her room. After half an hour of ironing, the light went off and Pinki went outside to

Triss [41]

Answer:

(a) An electric iron works on the heating effect of electric current

(b) The heating effect of an electric current is the tendency for electric current to cause the temperature of the material through which it is flowing to rise due to the resistance of the material

The heating effect, 'E', is given by the formula, E = I²·R·t

Where;

I = The current flowing

R = The resistance of the material

t = The time the material takes to heat up

(c) The values showed by Pinki here is the value of care, concern and prevention, to prevent the harmful effect of the high heat on the skin of her daughter

Explanation:

3 0

2 years ago

This is for Personal Financial Literacy:

bulgar [2K]

I’m sure “save” is the correct answer, as it is the only grammatically correct answer choice. Also, it is easy to save when you know what you’ll have to pay for in the future.

8 0

2 years ago

How do your shoe laces relate to a pulley

Margarita [4]

The grommets on your shoe (Holes through which you place the lace) act as the pulley. When you tighten at the top it restricts at the bottom and compresses around your foot.

The same can be applied to a pulley; If you have the proper set up Pulling one string causes two actions; the first being the most obvious. And the second being its effect. The Grommets of your shoe are the pulley's; while your Shoelaces are just the rope with which you operate the pulley.

8 0

3 years ago