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3 years ago

ANSWER ASAP - Define, describe and solve for speed, velocity, and acceleration

Physics

1 answer:

Vitek1552 [10]3 years ago

4 0

Answer:

Accelrtation:a vehicle's capacity to gain speed within a short time.EX:An object was moving north at 10 meters per second.

Velociy:the speed of something in a given direction EX:Velocity is the rate of motion, speed or action. An example of velocity is a car driving at 75 miles per hour.

Explanation:

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A marble rolls off a table from a height of 1.5 meters. Approximately how much time was the marble in the air?

sergij07 [2.7K]

Answer:

t = 0.55 s

Explanation:

Given that,

Height of the marble, h = 1.5 m

We need to find the time for which the marble is in air. Let the time is t. Using second equation of motion to find it as follows :

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

Here, u = 0 and a = g

$h=\dfrac{1}{2}gt^2\\\\t=\sqrt{\dfrac{2h}{g}} \\\\t=\sqrt{\dfrac{2\cdot1.5}{9.8}}\\\\t=0.55\ s$

So, the marble is in air for 0.55 s. Hence, the correct option is (c).

7 0

3 years ago

A cell phone charger operates at 5 volts and can deliver a maximum current of 1.0 Amp. If your cell phone has an energy storage

madam [21]

Answer:

it takes 2.16 hrs to fully charge the phone

Explanation:

V = 5v

I = 1A

E = 38.9 Kj = 38900 j

t = ?

E = IVt

t = E/IV

t = 38900 ÷ (1 × 5)

t = 38900 ÷ 5

t = 7780 seconds

t = 7780/3600............( converting time in seconds to hours)

t = 2.16 hrs

7 0

3 years ago

The electricity received at an electrical substation has a potential difference of 20,000 V. What should the ratio of the turns

iren2701 [21]

The turn ratio of the transformer is 40.

<h3 />

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

A transformer is an electrical device that is used to step up or step down voltage.

The formula for calculating the turns ratio of a transformer is given below.

<h3> Formula</h3>

a = V/v.......... Equation 1

Where:

V = Primary voltage
v = Secondary voltage
a = Turns ratio of the transformer

From the question,

Given:

V = 20000 V
v = 500 v

Substitute the values above into equation 1

a = 20000/500
a = 40.

Hence, The turn ratio of the transformer is 40.

Learn more about transformers here: brainly.com/question/6450076

7 0

3 years ago

What is the order of magnitude of the distance of Sun to nearest star in meters?

neonofarm [45]

Answer:

Approximating the Milky Way as a disk and using the density in the solar neighborhood, there are about 100 billion stars in the Milky Way.

Explanation:

Since we are making an order of magnitude estimate, we will make a series of simplifying assumptions to get an answer that is roughly right.

Let's model the Milky Way galaxy as a disk.

The volume of a disk is:

⋅

Plugging in our numbers (and assuming that

≈

)

⋅

(

)

⋅

(

)

Is the approximate volume of the Milky Way.

Now, all we need to do is find how many stars per cubic meter (

) are in the Milky Way and we can find the total number of stars.

Let's look at the neighborhood around the Sun. We know that in a sphere with a radius of

m there is exactly one star (the Sun), after that you hit other stars. We can use that to estimate a rough density for the Milky Way.

Using the volume of a sphere

(

)

256

−

stars /

Going back to the density equation:

Plugging in the density of the solar neighborhood and the volume of the Milky Way:

(

256

−

)

⋅

(

)

256

stars (or 100 billion stars)

Is this reasonable? Other estimates say that there are are 100-400 billion stars in the Milky Way. This is exactly what we found.

4 0

3 years ago

Read 2 more answers

A person jumps out a fourth-story window 14 m above a firefighter safety net. The survivor stretches the net 1.8 m before coming

Monica [59]

Answer:

The deceleration is $a = - 76.27 m/s^2$

Explanation:

From the question we are told that

The height above firefighter safety net is $H = 14 \ m$

The length by which the net is stretched is $s = 1.8 \ m$

From the law of energy conservation

$KE_T + PE_T = KE_B + PE_B$

Where $KE_T$ is the kinetic energy of the person before jumping which equal to zero(because to kinetic energy at maximum height )

and $PE_T$ is the potential energy of the before jumping which is mathematically represented at

$PE_T = mg H$

and $KE_B$ is the kinetic energy of the person just before landing on the safety net which is mathematically represented at

$KE_B = \frac{1}{2} m v^2$

and $PE_B$ is the potential energy of the person as he lands on the safety net which has a value of zero (because it is converted to kinetic energy )

So the above equation becomes

$mgH = \frac{1}{2} m v^2$

=> $v = \sqrt{2 gH }$

substituting values

$v = 16.57 m/s$

Applying the equation o motion

$v_f = v + 2 a s$

Now the final velocity is zero because the person comes to rest

$0 = 16.57 + 2 * a * 1.8$

$a = - \frac{16.57^2 }{2 * 1.8}$

$a = - 76.27 m/s^2$

4 0

3 years ago