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tensa zangetsu [6.8K]

3 years ago

14

A car takes off from a stop sign and is going 267 m/s after 4.5 seconds. a) Determine the acceleration of the car. Show your wor

k and include units

1 answer:

gizmo_the_mogwai [7]3 years ago

3 0

Answer:

49.33333m/s²

Explanation:

The formula for acceleration is <em>acceleration=change in velocity/change in time</em>

<em>So: </em>

<em>Iv= 0m/s</em>

<em>Fv= 267m/s</em>

<em>a=267m/s divided by 4.5s</em>

<em>a=49.3333m/s²</em>

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The speed of surface waves in water decreases as the water becomes shallower. Suppose waves travel across the surface of a lake

Elanso [62]

Answer:

The correct solution is "1.2 m".

Explanation:

The given values are:

Wavelength of waves,

λ = 1.5 m

Speed of waves on surface,

V = 2 m/sec

Speed of waves in water,

V₁ = 1.6 m/sec

As we know,

⇒ $V=f\times \lambda$

or,

⇒ $f=\frac{V}{\lambda}$

On substituting the values, we get

⇒ $=\frac{2}{1.5}$

⇒ $=1.33 \ Hz$

hence,

⇒ $\lambda_1=\frac{V_1}{f}$

On substituting the values, we get

⇒ $=\frac{1.6}{1.33}$

⇒ $=1.2 \ m$

7 0

3 years ago

Three noise sources produce volume (loudness) levels of 70, 73, and 80 dB when acting separately. When the sources act together,

Mashutka [201]

Sound at 70 dB is 70 dB louder than the human reference level. That's 10⁷ times as much as the reference sound power.

Sound at 73 dB is 73 dB louder than the human reference level. That's 10⁷.³ or 2 x 10⁷ times as much as the reference sound power.

Sound at 80 dB is 80 dB louder than the human reference level. That's 10⁸ or 10 x 10⁷ times as much as the reference sound power.

Now we can adumup:

Intensity of all 3 sources = (10⁷) + (2 x 10⁷) + (10 x 10⁷)

Intensity = (13 x 10⁷) times the sound power reference intensity.

Intensity in dB = 10 log (13 x 10⁷) = 10 (7 + log(13)

Intensity = 70 + 10 log(13)

Intensity = 70 + 10 (1.114)

Intensity = 70 + 11.14

Intensity = <em>81.14 dB</em>

<em>______________________________________</em>

Looking at the questioner's profile, I seriously wonder whether I'll ever get a comment in return from this creature, and how I'll ever find out if my solution is correct. For that matter, I'm also seriously questioning how and whether my solution will ever be used for anything.

8 0

3 years ago

Why pilots need to study navigation

masya89 [10]

To know where they’re heading to

3 0

4 years ago

Read 2 more answers

4. An object is thrown vertically upward with a speed of 25 m/s. How much time passes before it

vlada-n [284]

Answer:

<em>Option b is correct: 4.1 s</em>

Explanation:

<u>Vertical Launch</u>

An object launched thrown vertically upward where air resistance is negligible, reaches its maximum height in a time t, given by the equation:

$\displaystyle t=\frac{v_o}{g}\qquad\qquad[1]$

Where vo is the initial speed and g is the acceleration of gravity g=9.8 $m/s^2$ .

Once the object reaches that point, it starts a free-fall motion, whose speed is (downward) given by:

$v_f=g.t\qquad\qquad[2]$

The object considered in the question is thrown with vo=25 m/s. The time taken to reach the maximum height is given by [1]:

$\displaystyle t=\frac{25}{9.8}=2.551\ sec$

The object starts its falling motion and at some time, it has a speed of vf=15 m/s. Let's find the time by solving [2] for t:

$\displaystyle t=\frac{15}{9.8}=1.531\ sec$

The total time taken by the object to go up and down is

$t_t=2.551\ s+1.531\ s=4.081\ s$

a. This option is incorrect because it's far away from the answer.

d. This option is incorrect because it's far away from the answer.

b. This option is correct because it's a good approximation to the calculated answer.

e. This option is incorrect because it's far away from the answer.

c. This option is incorrect because it's far away from the answer.

5 0

3 years ago

How many 90-W, 120-V light bulbs can be connected to a 20-A, 120-V circuit without tripping the circuit breaker? (Note: This des

spayn [35]

Answer:

26

Explanation:

Total power of the circuit

P = V × I = 120 × 20 = 2400 W

Power of each bulb = 90 W

Number of bulbs which work without tripping

N = power of circuit / power of each bulb

N = 2400 / 90

N = 26.66

Number of bulbs should be integer so the number of bulbs be 26.

8 0

3 years ago