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Pachacha [2.7K]

3 years ago

9

To travel at constant speed, a car engine provides 24KW of useful power. The driving force on the car is 600N. At what speed doe

s it travel?

1 answer:

Keith_Richards [23]3 years ago

3 0

Answer:

The speed traveled by the car is 40 meter per second.

Explanation:

The formula for the relation between the power and the force is as follows:

P = Fv

Where F is the force and v is the speed.

As given

To travel at constant speed, a car engine provides 24KW of useful power. The driving force on the car is 600N.

F = 600 N

Convert power from KW to W.

1 KW = 1000 W

24 KW = 24 × 1000 W

= 24000 W

Thus

P = 24000 W

Put these values in the formula.

24000 = 600 × v

24000 = 600v

$v = \frac{24000}{600}$

v = 40 meter per second .

Therefore the speed of the car is 40 meter per second .

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A ball is droped from a height of 16m how much time will pass before the ball hits the ground

sergey [27]

Answer:

The time is 1.8s

Explanation:

The ball droped, will freely fall under gravity.

Hence we use free fall formula to calculate the time by the ball to hit the ground

$h= \frac{1}{2}g{t}^{2}$

Where h is the height from which the ball is droped, g is the acceleration due to gravity that acted on the ball, and t is the time taken by the ball to hit the ground.

From the question,

h=16m

Also, let take

$g = 9.8m{s}^{-2}$

By substitution we obtain,

$16= \frac{1}{2}\times 9.8{t}^{2}$

$\implies32=9.8{t}^{2}$

Diving through by 9.8

$\frac{32}{9.8}= \frac{ 9.8{t}^{2} }{9.8}$

$\implies{t}^{2} =3.265$

square root both sides, we obtain

$\implies t= \sqrt{3.265}$

$t=1.8s$

4 0

3 years ago

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

Bob and John are pulling in different directions. If Bob is pulling to the right with a force of 10N, and John is pulling to the

Oksi-84 [34.3K]

-- The net force on the box is 2N to the left.

-- The box will move to the left and accelerate to the left.

-- F=ma . a=F/m . a=(2N)/(4kg).

a = 0.5 m/s^2 to the left.

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The sound waves travel along this

Anna35 [415]

Explanation:

sound waves go through almost every thing exept solid walls

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1.)What are 3 diseases that you can pick up from school?

Amiraneli [1.4K]

Answer:

1. Lice, Pinworms, and Strep throat

2. Bathrooms, Desks, and Water fountain

3. Dry mouth, Rapid heartbeat, and headaches

Explanation:

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3 years ago