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2 years ago

Is

Physics

1 answer:

ivann1987 [24]2 years ago

4 0

Answer:

Required energy Q = 231 J

Explanation:

Given:

Specific heat of copper C = 0.385 J/g°C

Mass m = 20 g

ΔT = (50 - 20)°C = 30 °C

Find:

Required energy

Computation:

Q = mCΔT

Q = 20(0.385)(30)

Required energy Q = 231 J

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Formula to find gravitational potential energy:
mgh
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h: height (relative to reference level)

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3 years ago

A 3.0 m tall, 40 cm diameter concrete column supports a 235,000 kg load. by how much is the column compressed? assume young's mo

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The Young modulus E is given by:
$E= \frac{F L_0}{A \Delta L}$
where
F is the force applied
A is the cross-sectional area perpendicular to the force applied
$L_0$ is the initial length of the object
$\Delta L$ is the increase (or decrease) in length of the object.

In our problem, $L_0 = 3.0 m$ is the initial length of the column, $E=3.0 \cdot 10^{10}N/m^2$ is the Young modulus. We can find the cross-sectional area by using the diameter of the column. In fact, its radius is:
$r= \frac{d}{2}= \frac{40 cm}{2}=20 cm=0.2 m$
and the cross-sectional area is
$A=\pi r^2 = \pi (0.20 m)^2=0.126 m^2$
The force applied to the column is the weight of the load:
$W=mg=(235000 kg)(9.81 m/s^2)=2.305 \cdot 10^6 N$

Now we have everything to calculate the compression of the column:
$\Delta L = \frac{F L_0}{EA}= \frac{(2.305\cdot 10^6 N)(3.0 m)}{(3.0\cdot 10^{10}N/m^2)(0.126 m^2)} =1.83\cdot 10^{-3}m$
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3 years ago

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babunello [35]

Answer:

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2 years ago

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A person walks 30m due north, then 50m at 35 degrees. Find their total displacement.

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Using the cosine rule (a^2 = b^2 + c^2 - 2bc cos A), we can work out the displacement:
Displacement = a
b = 30
c = 50
A = 180 - 35 = 145 degrees.

a^2= 900 + 2500 -1500*-0.81915...
= 3400 + 1228.728...
= 4628.72...
a = 68.034...
= 68.0m (to 3s.f.).

To work out the angle from starting place, use another configuration of the cosine rule:
$cos(C)= \frac{a^{2} +b^{2}- c^{2} }{2ab}$ :
cos (C)= $\frac{4628.72...+900-2500}{2*68*30}$
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2 years ago

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Answer:

608.4m/s

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We are given that

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Speed of Sleigh,u=322 m/s

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