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2 years ago

The electric motor in the car is powered by a battery.

Physics

1 answer:

Vinil7 [7]2 years ago

6 0

Answer:

I = 30 A.

Explanation:

Given that,

The voltage of the battery, V = 230 V

Power used to charge the battery, P = 6.9 kW

We need to find the current used to charge the battery. The formula for the power is given by :

P = VI

Where

I is current

So,

So, the required current is 30 A.

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As a child walks, for a brief moment his entire weight is placed on one heel, which can be approximated as a small circle. Calcu

Brut [27]

The correct answer is option b, 63.6 kPa

Given,

The diameter of the heel, d=7 cm=0.07 m

The mass of the child, m=25 kg

The pressure is given by the ratio of the force to the area through which the force is applied.

The force applied on the floor by the child is equal to its weight.

Thus the pressure applied on the floor by the child is given by,

$\begin{gathered} P=\frac{F}{A} \\ =\frac{mg}{\pi(\frac{d}{2})^2} \end{gathered}$

Where A is the area of the cross-section of the heel.

On substituting the known values,

$\begin{gathered} P=\frac{25\times9.8}{\pi(\frac{0.07}{2})^2} \\ =63.6\times10^3\text{ Pa} \\ =63.6\text{ kPa} \end{gathered}$

Thus the pressure applied on the floor by the heel is 63.6 kPa

4 0

7 months ago

Which tools would sara us to find an irregularly shaped objects mass and volume A. a meter stick , a ruler , and water

tester [92]

I think it's D. Usually, to find the volume of an irregularly shaped object, you put it in water with a labeled beaker to measure how much the water rises. The balance would be used to measure the mass in grams.

4 0

2 years ago

Suppose that a sound source is emitting waves uniformly in all directions. If you move to a point twice as far away from the sou

Helen [10]

Answer:

<em>d. unchanged.</em>

Explanation:

The frequency of a wave is dependent on the speed of the wave and the wavelength of the wave. The frequency is characteristic for a wave, and does not change with distance. This is unlike the amplitude which determines the intensity, which decreases with distance.

In a wave, the velocity of propagation of a wave is the product of its wavelength and its frequency. The speed of sound does not change with distance, except when entering from one medium to another, and we can see from

v = fλ

that the frequency is tied to the wave, and does not change throughout the waveform.

where v is the speed of the sound wave

f is the frequency

λ is the wavelength of the sound wave.

4 0

2 years ago

Two friends leave a movie theater and take different busses to the same ice cream shop. One bus takes a longer route driving on

lisov135 [29]

Answer: short displacement has shorter road and long displacement has longer displacement . now think your self Which one is right

6 0

2 years ago

A maintenance worker wants to torque an engine bolt to 65.0 N m. If the torque wrench is 35cm in length, what is force applied t

harina [27]

Answer:

Force = 186 N

Explanation:

Torque is the rotational equivalent of linear force. It can be easely calculated using the formula :

$Torque = \vec{r} \times \vec{F}$

Where $\vec{r}$ is a vector that from the origin of the coordinate system to the point at which the force is applied (the position vector), $\vec{F}$ is the applied force.

The easiest way of computing the force is by setting the origin of the coordinate system to the lowest point of the torque wrench. By doing this we have that $r$ (the magnitud of the position vector) is 35cm.

Before computing the force we need to set all our values to the international system of units (SI). The torque is already in SI. The one missing is the length of the torque wrench (it is in centimeters and we need it in meters). So :

$35cm * \dfrac{1m}{100cm} = 0.35m$

Now using the torque formula:

$Torque = \vec{r} \times \vec{F}$

$Torque = rFsin(\theta)}$

Where $\theta$ is the smaller angle between the force and the position vector. Because the force is applied perpendiculary to the position vector $\theta = 90°$ , thus :

$Torque = rFsin(\theta)}$

$65 N m = (0.35m)Fsin(90°)}$

$F = \dfrac{65N m} {(0.35m)sin(90°)}$

$F = \dfrac{1300} {7}N$

so the force is approximately 186 N.

4 0

3 years ago