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3 years ago

11

The diagram shows a person holding a bow and arrow. Which will most likely increase the kinetic energy in this system? a not rel

easing the string b increasing the mass of the arrow c releasing the string d pulling back less on the string

1 answer:

Fantom [35]3 years ago

7 0

Answer:

b. Increasing the mass of the arrow.

Explanation:

The formula is K=1/2mv^2. Increasing the mass also increases the kinetic energy.

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Determine the molar concentration of 4 moles of HCL dissolved in 2500 ml of solution

Reptile [31]

Answer:

1.6 molar

Explanation:

C=number of moles/volume

convert ml to L

V =2.5L

C= 4/2.5

=1.6 molar

4 0

1 year ago

In the produce section of a supermarket, five pears are placed on a spring scale. The placement of the pears stretches the sprin

tankabanditka [31]

Answer:

The displacement of the spring due to weight is 0.043 m

Explanation:

Given :

Mass $m = 2$ Kg

Spring constant $k = 450 \frac{N}{m}$

According to the hooke's law,

$F = -kx$

Where $F =$ force, $x =$ displacement

Here,

$F = mg$ ( $g = 9.8 \frac{m}{s^{2} }$ )

$F = 2 \times 9.8 = 19.6$ N

Now for finding displacement,

$x = \frac{F}{k}$

Here minus sign only represent the direction so we take magnitude of it.

$x = \frac{19.6}{450}$

$x = 0.043$ m

Therefore, the displacement of the spring due to weight is 0.043 m

8 0

4 years ago

Saturn has a radius of about 9.0 earth radii, and a mass 95 times the Earth’s mass. Estimate the gravitational field on the surf

olchik [2.2K]

Answer:The gravitational field on Saturn can be calculated by the following formula;

Explanation:

6 0

4 years ago

Assume your car reaches a speed of 21.7 m/s at a steady rate for 5.05 s after the light turns green. (a) What distance have you

boyakko [2]

Answer:

The distance and average speed are 54.79 m and 10.85 m.

Explanation:

Given that,

Speed = 21.7 m/s

Time = 5.05 s

(a). We need to calculate the distance

Firstly we will find the acceleration

Using equation of motion

$v = u+at$

$a = \dfrac{v-u}{t}$

Where, v = final velocity

u = initial velocity

t = time

Put the value in the equation

$a = \dfrac{21.7-0}{5.05}$

$a = 4.297 m/s^2$

Now, using equation of motion again

For distance,

$s = ut+\dfrac{1}{2}at^2$

$s = 0+\dfrac{1}{2}\times4.3\times(5.05)^2$

$s=54.79\ m$

The distance is 54.79 m.

(b). We need to calculate the average speed during this time

$v_{avg}=\dfrac{D}{T}$

Where, D = total distance

T = time

Put the value into the formula

$v_{avg}=\dfrac{54.79}{5.05}$

$v_{avg}=10.85\ m/s$

Hence, The distance and average speed are 54.79 m and 10.85 m.

3 0

3 years ago

2. Explain the mechanism by which AC (alternating current) through the primary circuit of a transformer produces an alternating

atroni [7]

Explanation:

A transformer consists of core of soft iron (a material that can be easily magnetized/demagnetized), to which two coils are attached at both ends.

An alternating current in the primary coil produces a magnetic field around the coil, magnetizing the iron core; therefore, the same magnetic field produces a magnetic flux in the secondary coil.

Since the AC current in the primary coil is variable, then the magnetic field also changes, so the magnetic flux through the secondary coil changes over time; therefore, an electromotive force (and so, a current) is induced in the secondary coil, according to Faraday-Newmann-Lenz:

$\epsilon= - \frac{d\Phi}{dt}$

where

$\epsilon$ is the induced emf

$\frac{d\Phi}{dt}$ is the rate of change of magnetic flux through the secondary coil

We notice that this mechanism would not work if the current in the primary coil is a DC current: in fact, a DC current has always a constant value, so there is no change in the magnetic field, therefore no change in the magnetic flux through the secondary coil and no emf induced.

6 0

3 years ago