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3 years ago

Hekpppp!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Physics

1 answer:

kobusy [5.1K]3 years ago

7 0

1.chemical change:gas, order and liquid
2.physical change:color,soiled

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A 100-n object and a 50-n object are placed on scales a and b respectively inside an elevator ascending with constant velocity

german

Answer: b

Explanation:

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3 years ago

a resistor, of resistance 47 , is damaged when it dissipates a power greater than 0.5W. determine the maximum voltage that can b

harkovskaia [24]

Answer:

<em>The maximum voltage that can be applied without damaging the resistor is 4.85 V</em>

Explanation:

<u>Electric Power in a Resistor</u>

Given a resistor or resistance R connected to a circuit of voltage V carrying a current I. The relation between these three magnitudes is given by Ohm's Law:

V = R.I

The dissipated power P of a resistor can be calculated by the following equation, known as Joule's first law:

$P = I^2.R$

Solving the first equation for I:

$\displaystyle I=\frac{V}{R}$

Substituting in the second equation:

$\displaystyle P=\frac{V^2}{R^2}.R$

Simplifying:

$\displaystyle P=\frac{V^2}{R}$

Solving for V:

$V=\sqrt{P.R}$

The resistor has a resistance of R=47Ω and can hold a maximum power of P=0.5 W, thus the maximum voltage is:

$V=\sqrt{0.5\cdot 47}$

$V=\sqrt{23.5}$

V = 4.85 V

The maximum voltage that can be applied without damaging the resistor is 4.85 V

6 0

3 years ago

Which statement is true about the turbine in a hydroelectric dam? a. It is turned by wind and provides a direct current. b. It i

tresset_1 [31]

B) It is turned by water to produce a direct current....... hope it helps :)

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3 years ago

Which of the following does not represent a mechanical wave?

Sergeeva-Olga [200]

ocean waves because its not artificial

3 0

4 years ago

Read 2 more answers

Brian Berg of lowa built a house of cards 4.88 m tall. Suppose Berg throws a ball from ground level

Step2247 [10]

Answer:

Vf = final velocity = 1.96 [m/s]

Explanation:

To solve this problem we must use the following equation of kinematics.

$v_{f}^{2}=v_{o}^{2}-2*g*x$

where:

Vf = final velocity [m/s]

Vo = initial velocity = 9.98 [m/s]

g = gravity acceleration = 9.81 [m/s²]

x = vertical distance [m]

$v_{f}^{2}=(9.98)^{2}-2*9.81*4.88\\v_{f}^{2} = 99.6-95.74\\v_{f}=\sqrt{3.8544}\\v_{f}=1.96[m/s]$

Note: The negative sign of the gravity acceleration means that the gravity acceleration is pointing in the opposite direction of the movement.

4 0

3 years ago