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3 years ago

Find the initial velocity of a car which........

Physics

1 answer:

Alexandra [31]3 years ago

5 0

u = 25 m/s

Explanation:

<h3>Given Data,</h3>

$\sf\:\:\:\:\:\:\:\:\:\:\bullet\:Initial \:velocity,\: u=?$

$\sf\:\:\:\:\:\:\:\:\:\:\bullet\:Final\: velocity, \:v=0m/s$

$\sf\:\:\:\:\:\:\:\:\:\:\bullet\:Acceleration,\: a=−2.5m/s^2$ $\sf\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:| negative\:'cause\:$ $\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\sf \:\:\:\:\:\:\:\:it\:is\: deceleration|$

$\sf\:\:\:\:\:\:\:\:\:\:\bullet\:Time, \:t=10s$

$\:\:$

$\Large{\diamond}\:{\bold { \underline{\small{ Use\: the\: relation\: of \:the\: first\: eqn. \:of \:motion:}}}}$

$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\ddagger\underline{ \boxed{ \sf{v\:=\:u\:+\:at }}}$

$\:$

$\sf\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\leadsto\:0=u+(−2.5)×10$

$\:$

<h3> $\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\underline{\boxed{\sf{u=\frak{\red{25m/s}}}}}$ </h3>

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A plane mirror and a concave mirror (f = 8.40cm) are facing each other and are separated by a distance of 22.0 cm. An object is

lesya [120]

Answer:

The distance of the image produced by the concave mirror is 11.27 cm.

Explanation:

Given that,

Focal length = 8.40 cm

Distance between object and plane mirror = 11.0 cm

Distance between plane mirror and concave mirror = 22.0 cm

We need to calculate the object distance

$u =11.0+22.0 = 33.0\ cm$

We need to calculate the distance of the image

Using formula of distance of the image

$v=\dfrac{uf}{u-f}$

Where, u = Object distance

f = focal length

Put the value into the formula

$v=\dfrac{33.0\times8.40}{33.0-8.40}$

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Hence, The distance of the image produced by the concave mirror is 11.27 cm.

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3 years ago

A thermally isolated system consists of a hot piece of aluminum and a cold piece of copper. The aluminum and the copper are in t

Marrrta [24]

Answer:

the amount of heat that gets through both the wires will be same.

Explanation:

By the Fourier's law of conduction we have:

$\dot{Q}=k.A.\frac{dT}{dx}$

where:

$\dot{Q}$ = rate of heat transfer

k = thermal conductivity of the material

A = area of the material

dT = temperature difference across the length dx

According to the question, the system to be analysed is isolated from the surrounding.

Until the thermal equilibrium is established between aluminium and copper wires the amount of heat that gets through both the wires will be same.

<em>But the rate of heat transfer through the aluminium will be greater as it has double the thermal conductivity of copper.</em>

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3 years ago

A particle undergoes two displacements. The first has a magnitude of 11 m and makes an angle of 82 ◦ with the positive x axis. T

Luden [163]

Answer:

$\theta = 211.7 degree$

Explanation:

First displacement of the particle is given as

$r_1$ = 11 m at 82 degree with positive X axis

so we can say

$\vec r_1 = 11 cos82 \hat i + 11 sin82 \hat j$

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resultant displacement of the particle after second displacement is given as

r = 8.7 m at 135 degree with positive X axis

so we can say

$r = 8.7 cos135\hat i + 8.7 sin135\hat j$

$r = -6.15 \hat i + 6.15 \hat j$

now we know that

$r = r_1 + r_2$

now we have

$r_2 = r - r_1$

so we will have

$r_2 = (-6.15 \hat i + 6.15 \hat j) - (1.53\hat i + 10.9 \hat j)$

$r_2 = -7.68 \hat i - 4.75 \hat j$

so angle of the second displacement is given as

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$tan\theta = \frac{-4.75}{-7.68}$

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3 years ago

Jasper made a list of the properties of electromagnetic waves. Identify the mistake in the list. Electromagnetic Wave Properties

Nata [24]

Answer:

Statement 2 is wrong

Explanation:

To check the statements in this exercise, let's describe the main properties of electromagnetic waves. Let's describe the characteristics

* they are transverse waves

* formed by the oscillations of the electric and magnetic fields

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with these concepts let's review the final statements

1) True. Formed by the oscillation of the two fields

2) False. They are transverse waves

3) True. Can travel by vacuum as they are supported by oscillations of the electric and magnetic fields

4) True. They all have the same speed of light

Statement 2 is wrong

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4 years ago

A football was kicked so that it traveled 65 yards in 3.0 total seconds. What was the speed

Olin [163]

Answer:

vx = 65 yd/3 sec = 21.7 yd/sec since horizontal speed is constant

vy = g t = (32 / 3) yd/sec^2 * 1.5 sec = 16 yd/sec where 32/3 is the acceleration due to gravity in yds / sec^2 and 1.5 is the time to travel each way in the vertical direction

V = (vx^2 + vy^2)^1/2 = (21.7^2 + 16^2)^1/2 = 27 yd/sec

tan theta = vy/vx = 16 / 21.7 = .737 theta = 36.4 deg

You can check using the range formula:

R = v^2 sin (2 theta) / g = 27^2 * .955 / (32 / 3) = 65.3 yds

The difference from 65 yds may be rounding error.

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4 years ago

Find the initial velocity of a car which........ ​

Find the initial velocity of a car which........