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3 years ago

Which term describes the number of crests that pass a point in a given amount of time

2 answers:

7 0

The term is frequency.

The frequency is the number of vibrations per unit of time or the number of waves that passes a point per unit of time.

Every crest (and every trough) represents a pass of the wave so you can count the number of crests in an intervavl of time to find the frequency as the number of crests divided by the time elapsed.

anzhelika [568]3 years ago

5 0

The correct answer is Frequency.

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Which of the following statements are incorrect? a) The state of matter for an object that has a definite volume but not a defin

hoa [83]

Answer:

a), b), d), and e) are correct.

Explanation:

c) is incorrect because an object that has a definite shape cannot be in a gaseous state as gaseous objects take the shape of their container.

a) is correct because objects that are liquid have definite volumes but no definite shapes as they take the shape of their containers,

b) is correct as this is the definition of an object which is in a solid state.

d) is correct as this is the definition of an object which is in a gaseous state.

e) is correct as rigidness, the quality of having a definite shape is only exhibited by objects that are in solid state.

7 0

3 years ago

Cecily is inflating one of her bicycle tyres with the pump below. When she pushes the plunger down, does the volume of the gas i

Alexxandr [17]

Answer:

See the explanation below

Explanation:

This problem can be better understood graphically, so in the attached image we will use a diagram of a positive displacement air pump.

We can see that when she pushes the plunger, we see that the volume decreases.

8 0

3 years ago

A laser beam is incident at an angle of 30.2° to the vertical onto a solution of corn syrup in water. (a) If the beam is refract

mote1985 [20]

Answer:

a) n2 = 1.55

b) 408.25 nm

c) 4.74*10^14 Hz

d) 1.93*10^8 m/s

Explanation:

a) To find the index of refraction of the syrup solution you use the Snell's law:

$n_1sin\theta_1=n_2sin\theta_2$ (1)

n1: index of refraction of air

n2: index of syrup solution

angle1: incidence angle

angle2: refraction angle

You replace the values of the parameter in (1) and calculate n2:

$n_2=\frac{n_1sin\theta_1}{sin\theta_2}=\frac{(1)(sin30.2\°)}{sin18.82\°}=1.55$

b) To fond the wavelength in the solution you use:

$\frac{\lambda_2}{\lambda_1}=\frac{n_1}{n_2}\\\\\lambda_2=\lambda_1\frac{n_1}{n_2}=(632.8nm)\frac{1.00}{1.55}=408.25nm$

c) The frequency of the wave in the solution is:

$v=\lambda_2 f_2\\\\f_2=\frac{v}{\lambda_2}=\frac{c}{n_2\lambda_2}=\frac{3*10^8m/s}{(1.55)(408.25*10^{-9}m)}=4.74*10^{14}\ Hz$

d) The speed in the solution is given by:

$v=\frac{c}{n_2}=\frac{3*10^8m/s}{1.55}=1.93*10^8m/s$

8 0

3 years ago

standing side by side, you and a friend step off a bridge and fall for 1.6s to the water below. your friend goes first, and you

Andrew [12]

(a) The distance will be more than 2.0 meters.

In fact, you starts your fall after your friend has already fallen 2.0 meters. This means that your friend has already accelerated for a while, therefore his velocity will be greater than yours. But this statement will be actually true for the entire fall, since you has some delay, therefore when your friend will hit the water, the separation between you and him will be greater than the initial separation of 2.0 meters.

b) First of all we need to calculate the height of the bridge with respect to the water. We know that you take 1.6 s to fall down, therefore we can use the following equation:

$S=\frac{1}{2}gt^2=\frac{1}{2}(9.81 m/s^2)(1.6s)^2=12.56 m$

We know that your friend will take 1.6 s to falls down. Instead, you start your jump after he has already fallen 2.0 m, therefore after a time given by the equation:

$S=\frac{1}{2}gt^2$

Using S=2.0 m,

$t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(2.0 m)}{9.81 m/s^2}}=0.64 s$

So we know that you start your fall 0.64 s after your friend. Therefore, now we can find how much did you fall between the moment you started your fall (0.64 s) and the moment your friend hits the water (1.6 s). Using

$t=1.6 s-0.64 s=0.96 s$

we find

$S=\frac{1}{2}gt^2=\frac{1}{2}(9.81 m/s^2)(0.96 s)^2 =4.52 m$

So, when your friend hits the water, you just covered 4.52 m, while he already covered 12.56 m. Therefore, the separation between you and your friend is more than 2 meters.

8 0

3 years ago

The driver of a 2.0 × 10³ kg red car traveling on the highway at 45m/s slams on his brakes to avoid striking a second yellow car

nignag [31]

Answer:

Explanation:

a = F/m = 7500/2000 = 3.75 m/s²

v² = u² + 2as

s = (v² - u²) / 2a

s = (0² - 45²) / (2(-3.75))

s = 270 m

6 0

2 years ago