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4 years ago

A falling object accelerates from -10.0 m/s to -30.0 m/s. how much time does it take?

Physics

2 answers:

Zepler [3.9K]4 years ago

8 0

Answer:

2.04 s

Explanation:

v = at + v₀

(-30.0 m/s) = (-9.8 m/s²) t + (-10.0 m/s)

t = 2.04 s

KIM [24]4 years ago

8 0

<u>Answer</u>:

The time taken by the falling object is 2.04 sec

<u>Solution:</u>

The initial velocity $V = -10 m/s$

The final velocity $V_1 = -30m/s$

Let us assume that the time taken is t sec

We know that the acceleration due to gravity $g = 9.8m/sec^2$

As per the free falling object motion,

$V_1 = V -gt$

$-30 = -10 -9.8\times t$

$-30+10 = -9.8\times t$

$-20 = -9.8\times t$

$t =\frac{20}{9.8} = 2.04$

So, it takes total 2.04 sec

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84. Three resitors each of value 30 respectively are connected in a parallel

kati45 [8]

Answer:

each resistor draws 1/3 of an amp or 0.33333 amps

Explanation:

V = I * R

V = 10 volts

R = 30 ohms

10 = I * 30 Divide by 30

10/30 = I

I = 0.33333

8 0

3 years ago

A circular radar antenna on a Coast Guard ship has a diameter of 2.10 m and radiates at a frequency of 16.0 GHz. Two small boats

Anna35 [415]

Answer:

d = 76.5 m

Explanation:

To find the distance at which the boats will be detected as two objects, we need to use the following equation:

$\theta = \frac{1.22 \lambda}{D} = \frac{d}{L}$

<u>Where:</u>

θ: is the angle of resolution of a circular aperture

λ: is the wavelength

D: is the diameter of the antenna = 2.10 m

d: is the separation of the two boats = ?

L: is the distance of the two boats from the ship = 7.00 km = 7000 m

To find λ we can use the following equation:

$\lambda = \frac{c}{f}$

<u>Where:</u>

c: is the speed of light = 3.00x10⁸ m/s

f: is the frequency = 16.0 GHz = 16.0x10⁹ Hz

$\lambda = \frac{c}{f} = \frac{3.00 \cdot 10^{8} m/s}{16.0 \cdot 10^{9} s^{-1}} = 0.0188 m$

Hence, the distance is:

$d = \frac{1.22 \lambda L}{D} = \frac{1.22*0.0188 m*7000 m}{2.10 m} = 76.5 m$

Therefore, the boats could be at 76.5 m close together to be detected as two objects.

I hope it helps you!

7 0

3 years ago

What color of light must blue light mix with to create white light?

schepotkina [342]

<h2>Answer: a. Yellow </h2>

According to the additive theory of color, when we join the <u>three primary colors of light</u> (Red + Green + Blue) we get White light.

On the other hand we have <u>secondary colors of ligh</u>t that are:

Yellow = Red + Green

Magenta = Blue + Red

Cyan = Blue + Green

Now, if we know that:

Red + Green + Blue = White

And:

Red + Green = Yellow

Then:

<h2>Yellow + Blue = White</h2>

5 0

3 years ago

Two toroidal solenoids are wound around the same form so that the magnetic field of one passes through the turns of the other. S

dedylja [7]

The concept that we need here to give a proper solution is mutual inductance.

The mutual inductance is given by the expression

$M=\frac{N\Phi}{I}$

Where,

I = current

N = Number of turns

$\Phi =$ Flux through the solenoid.

Part A) Then we have in our values that,

$I=6.6A$

$\Phi= 3.50*10^{-2}Wb$

$N=450$

Replacing in the equation,

$M = \frac{450*350*10^{-2}}{6.60}$

$M = 2.39H$

Part B) Here is required the Flux, then using the same expression we have that

$\Phi = \frac{IM'}{N}$

We conserve the same value for the Inductance but now we have a current of 2.6, then

$\Phi = \frac{2.6*2.39}{690}$

$\Phi = 9*10^{-3}Wb$

Therefore the flux in Solenoid 1 is $9*10^{-3}Wb$

8 0

3 years ago

A spring scale exerts a net force of 8.5 N on an object. What is the object's mass if it has an acceleration of

Amiraneli [1.4K]

Answer:

mass of the object is 2.18 kg

Explanation:

Given

Force (F) = 8.5 N = 8.5 kg.m/ $s^{2}$

acceleration (a) = 3.9 m/ $s^{2}$

Mass (m) = ?

We know that the newton's second law of motion gives the relation between mass of ab object. force acted upon and the amount the object is accelerated. It is expressed in the form of an equation:

F = ma

mass, m = F/a

= $\frac{8.5 kgms^{-2} }{3.9 ms^{-2} }$

= 2.18 kg

4 0

3 years ago