All categories

3 years ago

A bird can fly 25 km/h. How long does it take to fly 3.5km?

Physics

1 answer:

monitta3 years ago

6 0

The equation of motion that we can use in this case is:

t = d / v

where t is time, d is distance, v is velocity

Therefore calculating for t:

t = 3.5 km / (25 km / h)

t = 0.14 h = 8.4 minutes

You might be interested in

In which medium does light travel faster: one with a critical angle of 27.0° or one with a critical angle of 32.0°? Explain. (Fo

Eddi Din [679]

Answer:

Among those two medium, light would travel faster in the one with a reflection angle of $32^{\circ}$ (when light enters from the air.)

Explanation:

Let $v_{1}$ denote the speed of light in the first medium. Let $v_{\text{air}}$ denote the speed of light in the air. Assume that the light entered the boundary at an angle of $\theta_{1}$ to the normal and exited with an angle of $\theta_{\text{air}}$ . By Snell's Law, the sine of $\theta_{1}\!$ and $\theta_{\text{air}}\!$ would be proportional to the speed of light in the corresponding medium. In other words:

$\displaystyle \frac{v_{1}}{v_{\text{air}}} = \frac{\sin(\theta_{1})}{\sin(\theta_{\text{air}})}$ .

When light enters a boundary at the critical angle $\theta_{c}$ , total internal reflection would happen. It would appear as if the angle of refraction is now $90^{\circ}$ . (in this case, $\theta_{\text{air}} = 90^{\circ}$ .)

Substitute this value into the Snell's Law equation:

$\begin{aligned}\frac{v_{1}}{v_{\text{air}}} &= \frac{\sin(\theta_{1})}{\sin(\theta_{\text{air}})} \\ &= \frac{\sin(\theta_{c})}{\sin(90^{\circ})} \\ &= \sin(\theta_{c})\end{aligned}$ .

Rearrange to obtain an expression for the speed of light in the first medium:

$v_{1} = v_{\text{air}} \cdot \sin(\theta_{1})$ .

The speed of light in a medium (with the speed of light slower than that in the air) would be proportional to the critical angle at the boundary between this medium and the air.

For $0 < \theta < 90^{\circ}$ , $\sin(\theta)$ is monotonically increasing with respect to $\theta$ . In other words, for $\!\theta$ in that range, the value of $\sin(\theta)\!$ increases as the value of $\theta\!$ increases.

Therefore, compared to the medium in this question with $\theta_{c} = 27^{\circ}$ , the medium with the larger critical angle $\theta_{c} = 32^{\circ}$ would have a larger $\sin(\theta_{c})$ . such that light would travel faster in that medium.

4 0

3 years ago

Relative means

Bond [772]

Answer:As a noun relative means a person who is connected with others by blood.

7 0

2 years ago

Which two questions can be used to identify criteria for how successful the design of an efficient high altitude drone is?

AfilCa [17]

Answer:

Explanation:

Remark

Though you do not know what height the previous drone reached, I would think reading 8000 m would be quite an accomplishment. Answer 1: A

B: I wouldn't pick B. Increased cost isn't going to contribute to design success.

C. If the efficiency is low to start with, increasing it some won't matter. On the other hand if the efficiency is moderate or good increasing it by 35% is a good thing. Let's hold on to this answer.

D: It has to work at low altitudes in order to work at high altitudes. I wouldn't pick D

E: Popularity is something you never know will happen. I think C is your best second answer.

Answer: A and C

7 0

2 years ago

Need help with these physic questions!

gtnhenbr [62]

Explanation:

Given: Δd = 4 + 2 + 1 = 7km, Δt = 32 + 22 + 16 = 70mins

Required: V

Equation: V = Δd/Δt

Solution: V = 7/70

= 0.1km/min

6 0

3 years ago

A father places his daughter in a swing that is 0.60\,\text{m}0.60m0, point, 60, start text, m, end text above ground. Then he r

schepotkina [342]

This question involves the concepts of the law of conservation of energy and kinetic energy.

The girl's fastest speed is "3.7 m/s".

According to the law of conservation of energy, the girl will have the fastest speed at mean position, which will be calculated as follows:

Loss in Potential Energy = Gain in Kinetic Energy

$mg\Delta h=\frac{1}{2}mv^2\\\\v=\sqrt{2g\Delta h}$

where,

v = maximum speed = ?

g = acceleration due to gravity = 9.81 m/s²

Δh = change in height = 1.3 m - 0.6 m = 0.7 m

Therefore,

$v=\sqrt{2(9.81\ m/s^2)(0.7\ m)}$

v = 3.7 m/s

Learn more about the Law of Conservation of Energy here:

brainly.com/question/381281?referrer=searchResults

5 0

2 years ago