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3 years ago

A car travels 200m in 30 s and 400m in the next 90s. Whats the average speed?

Physics

1 answer:

VLD [36.1K]3 years ago

6 0

Answer:

300m per minute or 5m per second

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Sound is produced by

elena-14-01-66 [18.8K]

Sound is produced when something <span>vibrates.

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7 0

3 years ago

Read 2 more answers

Suppose that a public address system emits sound uniformly in all directions and that there are no reflections. The intensity at

dybincka [34]

Answer:

The intensity at a spot 71 m away is $4.02*10^{-5} Wm^{-2}$

Explanation:

Given:

Initial intensity, $I_{1}=3.0*10^{-4} Wm^{-2}$ at a distance, $d_{1} = 26 m$

Required:

New intensity, $I_{2} =?$ at a distance, $d_{2} = 71 m$

Using the inverse square law,

I ∝ $\frac{1}{d^{2} }$

⇒ $I_{1}$ $I_{1}d_{1}^{2} =I_{2}d_{2}^{2}$

$I_{2} =\frac{I_{1} d_{1}^{2} }{d_{2}^{2}} =\frac{3.0*10^{-4}*26^{2} }{71^{2} } \\$ ×

$I_{2}=4.02*10^{-5} Wm^{-2}$

Thus, the intensity at a spot that is 71 m away is $4.02*10^{-5} Wm^{-2}$

5 0

3 years ago

Can someone please help!!

frosja888 [35]

Answer:

Weight needed to balance the bar is $8.5N$

Explanation:

Given the weight of the bar is $8N$

The length of the bar is $5m$

The weight of the bar will be uniformly distributed over the entire span. We will consider this as a point load acting in the middle of span length, which is at a distance of $2.5m$ from both ends.

Now applying momentum equation about balanced load we get, (see attachment)

$\sum m_i=0\\2(m)+8(1)-8(0.5)-7(3)=0\\2m+8-4-21=0\\2m-17=0\\2m=17\\m=\frac{17}{2}=8.5\\So,\ m=8.5N$

7 0

3 years ago

Calculate the horizontal projectile range with the cannon elevated 6m above the x-axis, with an initial speed of 14 m/s and an i

Paul [167]

Answer:

d = 20.25 m

Explanation:

h = 6m, V = 14 m/s, θ=14°

⇒ Vx=V × Cosθ=13.58 m/s and Vy = V × Sinθ=3.39 m/s

to find time t by h=-Vy t + 1/2 g t² (after putting value and simplifying) (-ve for downward motion)

4.9 t² - 3.39 t - 6 =0

⇒ t=1.5 sec (ignoring -ve root)

Now Vx = d/t

13.5 m/s = d / 1.5 s ⇒ d = 20.25 m

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3 years ago

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What does a force acting on an object do to that object';s motion?

ch4aika [34]

Accourding to newtons second law of motion:
Force = mass * acceleration
F = ma
a = F/m

8 0

3 years ago