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zhannawk [14.2K]
3 years ago
9

A block of mass = 4.00 kg is supported by a spring scale with unit of measure of Newtons. This spring scale is attached to top o

f an elevator. The elevator accelerates upward with a = 3.00 m/sec2. What is the reading on the spring scale to 3 significant figures?
Physics
1 answer:
faust18 [17]3 years ago
5 0

Answer:

118 N

Explanation:

Given mass of the block, m = 4.00kg.

The acceleration of the elevator, a = 3.0 m/s^2.

As elevotar attaced with spring scale and accelerating upward

(block and elevator), so total force

F_N-mg=ma

Here, mg is the weight of the block downward direction.

or

F_N=ma+mg=m(g+a)

substitute the given value, we get

F_N=4kg(9.8m/s^2+3m/s^2)

     = 117.6 N = 118 N.

Thus, the reading on the spring scale to 3 significant figures is 118 N.

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A current of 0.001 A can be felt by the human body. 0.005 A can produce a pain response. 0.015 A can cause a loss of muscle cont
lys-0071 [83]

Answer:

In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.

Explanation:

The current flowing through your system is described by Ohm's law

        V = I R

where I is the current, V the voltage and R the resistance

in this case three barateras are taken in series giving a total voltage of V = 4.5 V the typical resistance values ​​of dry skin is R = 1000 000Ohm and the resinification of wet skin is R = 100000 ohm

let's calculate the current flowing

        I = V / R

        I = 4.5 / 1000000

        I = 4.5 10⁻⁶ A

this is the current with dry hands, we see that much less than the value that allows to feel a painful response by the body

If the skin is

         I = 4,5 / 100,000

         I = 4.5 10⁻⁵ A

This value is small, but it is close to the pain threshold, but it is in the range of slight discomfort.

In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.

7 0
3 years ago
A train travels 99 kilometers in 2 hours, and then 90 kilometers in 3 hours. What is its average speed?
Agata [3.3K]

Average speed =

(total distance)/(total time)

Average speed = (99+90)/(2+3)

That's (189 km) / (5 hr)

Average speed = 37.8 km/hr

3 0
3 years ago
What is the frequency of a photon with an energy of 4. 56 x 10^-19 j
Sauron [17]

The frequency of a photon with an energy of 4.56 x 10⁻¹⁹ J is 6.88×10¹⁴ s⁻¹.

<h3>What is a frequency?</h3>

The number of waves that travel through a particular point in a given length of time is described by frequency. So, if a wave takes half a second to pass, the frequency is 2 per second.

Given that the energy of the photon is 4.56 x 10⁻¹⁹ J. Therefore, the frequency of the photon can be written as,

\rm \gamma = \dfrac{E}{h} = \dfrac{4.56x10^{-19} J}{6.626 \times 10^{-34}\ Jsec^{-1}}\\\\\\\gamma  = 6.88 \times 10^{14}\ s^{-1}

Hence, the frequency of a photon with an energy of 4.56 x 10⁻¹⁹ J is 6.88×10¹⁴ s⁻¹.

Learn more about Frequency:

brainly.com/question/5102661

#SPJ4

5 0
2 years ago
Read 2 more answers
Which of the following foods contains large amounts of protein? chicken, beans, fish, dairy, berries
d1i1m1o1n [39]

Answer: chicken hope this helps!

Explanation:

3 0
3 years ago
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Determine which heat transfers below are due to the process of conduction. I) You walk barefoot on the hot street and it burns y
Taya2010 [7]

Answer:

I) You walk barefoot on the hot street and it burns your toes.

II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.

Explanation:

In conduction mode of heat transfer we know that the energy is transferred from one system to other system due to direct contact of two bodies

Here due to this direct contact the energy is transferred via a given solid or liquid medium

In this type of heat transfer medium particles will remain in its own position only the energy is transferred.

So here we can say the correct answer will be

I) You walk barefoot on the hot street and it burns your toes.

II) When you get into a car with hot black leather in the middle of the summer and your skin starts to get burned.

3 0
4 years ago
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