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4 years ago

WILL UPVOTE!!!Physics help please!!

Physics

1 answer:

liubo4ka [24]4 years ago

8 0

Speed v = initial speed u + acceleration a x time t
v=u+at = 2 + 4*3 = 14 m/s

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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:

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

Explanation:

Electric Power in a Resistor

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

A crane raises a crate with a mass of 150 kg to a height of 20 m. Given that

Virty [35]

Answer:

$\boxed {\boxed {\sf 29,400 \ Joules}}$

Explanation:

Gravitational potential energy is the energy an object possesses due to its position. It is the product of mass, height, and acceleration due to gravity.

$E_P= m \times g \times h$

The object has a mass of 150 kilograms and is raised to a height of 20 meters. Since this is on Earth, the acceleration due to gravity is 9.8 meters per square second.

m= 150 kg
g= 9.8 m/s²
h= 20 m

Substitute the values into the formula.

$E_p= 150 \ kg \times 9.8 \ m/s^2 \times 20 \ m$

Multiply the three numbers and their units together.

$E_p=1470 \ kg*m/s^2 \times 20 m$

$E_p=29400 \ kg*m^2/s^2$

Convert the units.

1 kilogram meter square per second squared (1 kg *m²/s²) is equal to 1 Joule (J). Our answer of 29,400 kg*m²/s² is equal to 29,400 Joules.

$E_p= 29,400 \ J$

The crate has 29,400 Joules of potential energy.

7 0

3 years ago

A pendulum of length L = 1 m is released from an initial angle of 15° . After 1000 s, its amplitude is reduced to 2.5º. What is

jonny [76]

Answer:

The value of the time constant is 558.11 sec.

Explanation:

Given that,

Pendulum length = 1 m

Initial angle = 15°

Time = 1000 s

Reduced amplitude = 2.5°

We need to calculate the value of the time constant

Using formula of damping oscillation

$\theta=\theta_{0}e^{\dfrac{t}{\tau}}$

Where, $\theta$ =amplitude

$\theta_{0}$ =amplitude at t = 0

Put the value into the formula

$2.5=15e^{\dfrac{-1000}{\tau}}$

$\dfrac{1}{6}=e^{\dfrac{-1000}{\tau}}$

$ln\dfrac{1}{6}=\dfrac{-1000}{\tau}$

$\tau=\dfrac{1000}{-ln\dfrac{1}{6}}$

$\tau=558.11\ sec$

Hence, The value of the time constant is 558.11 sec.

6 0

3 years ago

A sample contains 10g of radioactive isotope. How much radioactive isotope will remain in the sample after 3 half-lives?

Ainat [17]

Answer:

After 1 half-life (500 years), 500 g of the parent isotope will remain. After 2 half-lives (1000 years), 250 g of the parent isotope will remain. After 3 half-lives (1500 years), 125 g of the parent isotope will remain. After 4 half-lives (2000 years), 62.5 g of the parent isotope will remain.

Explanation:

3 0

3 years ago

2H2+O2---> 2H2O can be classified as what type of reaction?

alisha [4.7K]

I believe the answer is B

3 0

4 years ago