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blondinia [14]
3 years ago
13

An automobile travels on a straight road for 40 km at 30 km/h. It then continues in the same direction for another 40 km at 60 k

m/h. (a) What is the average velocity of the car during the full 80 km trip? (Assume that it moves in the positive x direc
Physics
1 answer:
Butoxors [25]3 years ago
6 0

Answer:

The average velocity is 40km/h.

Explanation:

The average velocity is \bar{v}=\frac{\Delta x }{\Delta t}, where \Delta x is the distance traveled and \Delta t the time elapsed.

The distance traveled is clearly 80km since it's all done in the same direction, we only need to know the time elapsed. For this we calculate the time elapsed on the first part, and add it to the time elapsed on the second part using always the formula \Delta t=\frac{\Delta x }{v}, where v is the velocity on each part, which is constant.

The time elapsed for the first part is \Delta t_1=\frac{40 km}{30km/h}=\frac{4}{3}h, and the time elapsed for the second part is \Delta t_2=\frac{40 km}{60km/h}=\frac{2}{3}h, giving us a total time of \Delta t_1+\Delta t_2=\frac{4}{3}h+\frac{2}{3}h=2h.

Finally, we can calculate the average velocity: \bar{v}=\frac{80km}{2h}=40km/h.

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INK]: A car is moving at 200 km/hr east. What is its velocity?
Greeley [361]

Answer:

200 km\h

or 0.621 mp\h its the same speed just different mesuarements

5 0
3 years ago
We have a toy gun with a spring constant of 50 N/m. The spring is compressed by 0.2 m. If you neglect friction and the mass of t
Arisa [49]

Answer:

31.6\:\mathrm{m/s}

Explanation:

The elastic potential energy of a spring is given by Us=\frac{1}{2}kx^2, where k is the spring constant of the spring and x is displacement from point of equilibrium.

When released, this potential energy will be converted into kinetic energy. Kinetic energy is given by KE=\frac{1}{2}mv^2, where m is the mass of the object and v is the object's velocity.

Thus, we have:

Us=KE,\\\frac{1}{2}kx^2=\frac{1}{2}mv^2

Substituting given values, we get:

\frac{1}{2}\cdot 50\cdot 0.2^2=\frac{1}{2}\cdot 0.002\cdot v^2,\\v^2=\frac{50\cdot 0.2^2}{0.002},\\v^2=1000,\\v\approx \boxed{31.6\:\mathrm{m/s}}

4 0
3 years ago
Why does conduction occur more slowly in gases than in solids?​
Nataly [62]
Onduction in gas is slower than in liquids and solids because the particles in a gas collide less often. Conduction in metals is faster because the electrons are free to move about
4 0
3 years ago
When a honeybee flies through the air, it develops a charge of +20 pC . Part A How many electrons did it lose in the process of
Yuri [45]

Answer:

1.3 × 10⁸ e⁻

Explanation:

When a honeybee flies through the air, it develops a charge of +20 pC = + 20 × 10⁻¹² C. This is a consequence of losing electrons (negative charges). The charge of 1 mole of electrons is 96468 C (Faraday's constant). The moles of electrons representing 20 pC are:

20 × 10⁻¹² C × (1 mol e⁻/ 96468 C) = 2.1 × 10⁻¹⁶ mol e⁻

1 mole of electrons has 6.02 × 10²³ electrons (Avogadro's number). The electrons is 2.1 × 10⁻¹⁶ moles of electrons are:

2.1 × 10⁻¹⁶ mol e⁻ × (6.02 × 10²³ e⁻/ 1 mol e⁻) = 1.3 × 10⁸ e⁻

7 0
4 years ago
When monochromatic light shines perpendicularly on a soap film (n = 1.33) with air on each side, the second smallest nonzero fil
Anika [276]

Let us start from considering monochromatic light as an incidence on the film of a thickness t whose material has an index of refraction n determined by their respective properties.

From this point of view part of the light will be reflated and the other will be transmitted to the thin film. That additional distance traveled by the ray that was reflected from the bottom will be twice the thickness of the thin film at the point where the light strikes. Therefore, this relation of phase differences and additional distance can be expressed mathematically as

2t + \frac{1}{2} \lambda_{film} = (m+\frac{1}{2})\lambda_{film}

We are given the second smallest nonzero thickness at which destructive interference occurs.

This corresponds to, m = 2, therefore

2t = 2\lambda_{film}

t = \lambda_{film}

The index of refraction of soap is given, then

\lambda_{film} = \frac{\lambda_{vacuum}}{n}

Combining the results of all steps we get

t = \frac{\lambda_{vacuum}}{n}

Rearranging, we find

\lambda_{vacuum} = tn

\lambda_{vacuum} = (278)(1.33)

\lambda_{vacuum} = 369.74nm

4 0
3 years ago
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