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2 years ago

Please answer and show work

Physics

1 answer:

Lyrx [107]2 years ago

8 0

Answer:

v2 = v1 + at

a acceleration

t time

v2 final velocity v1 initial velocity

v2 = 30 + -4*3 =

30 -12 = 18m/s

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If one light bulb burns out in a string of lights, and the rest stay lit, it is reasonable to assume that the lights are wired i

Blizzard [7]

The lights are wired in PARALLEL.

In fact, when the lights are connected in parallel, they are connected on separate branches to the source of voltage, so if one light bulb burns out, the other lights continue to work because the current continues to flow in the other branches of the circuit.

Vice-versa, if the light bulbs are connected in series, they are on the same branch This means that if one of them burns out, the circuit is open in that point, so the current cannot flow anymore and the other light bulbs turn off as well.

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3 years ago

What are stepdown transformers used for

lesya692 [45]

Answer:

Step down transformers are used in power adaptors and rectifiers to efficiently decrease the voltage. They are also used in electronic SMPS.

Explanation:

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3 years ago

On a smooth horizontal floor an object

lukranit [14]

Answer:

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Explanation:

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3 years ago

Read 2 more answers

A 0.6 kg block attached to a spring of force constant 13.6 N/m oscillates with an amplitude of 9 cm. Find the maximum speed of t

mash [69]

Answer:

1) 0.43 meters per second

2) 0.21 meters per second

3) 1.02 $\frac{m}{s^{2}}$

4) 0.66 seconds

Explanation:

part 1

By conservation of energy, the maximum kinetic energy (K) of the block is at equilibrium point where the potential energy is zero. So, at the equilibrium kinetic energy is equal to maximum potential energy (U):

$K=U$

$\frac{mv^2}{2}=\frac{kx_{max}^2}{2}$

With m the mass, v the speed, k the spring constant and xmax the maximum position respect equilibrium position. Solving for v

$v=\sqrt{\frac{kx_{max}^2}{m}}=\sqrt{\frac{(13.6)(0.09m)^2}{0.6}}=0.43\frac{m}{s}$

part 2

Again by conservation of energy we have kinetic energy equal potential energy:

$\frac{mv^2}{2}=\frac{kx_{max}^2}{2}=$

$v=\sqrt{\frac{kx_{max}^2}{m}}=\sqrt{\frac{(13.6)(0.045m)^2}{0.6}}=0.21\frac{m}{s}$

part 3

Acceleration can be find using Newton's second law:

$F=ma$

with F the force, m the mass and a the acceleration, but elastic force is -kx, so:

$-kx=ma$

$a= -\frac{kx}{m}=-\frac{(13.6)(0.045)}{0.6}=-1.02\frac{m}{s^{2}}$

part 4

The period of an oscillator is the time it takes going from one extreme to the other one, that is going form 4.5 cm to -4.5 cm respect the equilibrium position. That period is:

$T=2\pi\sqrt{\frac{m}{k}}=T=2\pi\sqrt{\frac{0.6}{13.6}}=1.32s$

So between 0 and 4.5 cm we have half a period:

$t=\frac{T}{2}=0.66s$

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3 years ago

Look at the periodic table which statement about the elements on the periodic table is true

IRINA_888 [86]

Answer: B

Explanation:

The reactivity of alkaline metal ( example group one ) increases down the group because of the increase in atomic mass from the top to the bottom of the group. As the mass increases, the force between the nucleus and the valence electron gets weaker and the atom will easily give up the electron as a result of this which eventually increases its reactivity.

The reactivity of halogens decreases as atomic mass increases. Therefore, option B is the correct answer.

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4 years ago