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Phantasy [73]
3 years ago
15

A runner starts from a rest and speeds up with a constant acceleration . if she has gone a distance of 30 m at the point when sh

e reaches a speed of 8 m/s what is her acceleration
Physics
2 answers:
garik1379 [7]3 years ago
6 0

Answer:

a = 1.07 m/s^2

Explanation:

As we know that the runner starts from rest position

So here we can say

v_i = 0

now the distance moved by the runner is given as

d = 30 m

also we know that final speed of the runner will be

v_f = 8 m/s

now we know that

v_f^2 - v_i^2 = 2 a d

8^2 - 0 = 2(a)(30)

a = \frac{64}{60}

a = 1.07 m/s^2

arsen [322]3 years ago
5 0

Answer:

1.1 m/s

Explanation:

Apex

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After driving a portion of the route, the taptap is fully loaded with a total of 27 people including the driver, with an average
lara [203]

Answer:

compression of spring is x = 0.12 m

Assumed k = 160,000 N/m ........ Truck's suspension system

Explanation:

Given:

- The mass of average person m_p = 69 kg

- Total number of persons n_p = 27

- The mass of each goat m_g = 15 kg

- The total number of goats n_g = 3

- The mass of each chicken m_c = 3 kg

- The total number of goats n_c = 5

- The total mass of bananas m_b = 25 kg

Find:

How much are the springs compressed?

Solution:

- Using equilibrium equation on the taptap in vertical direction:

                                 F_net = F_spring - F_weight = 0

- Compute the force due to all the weights on the taptap:

                                F_weight = (n_p*m_p + n_g*m_g + n_c*m_c + m_b)*9.81

                                F_weight = (69*27 + 3*15 + 5*3 + 25)*9.81  

                                F_weight = 19109.88 N

- The restoring force of a spring is given by:

                                F_spring = k*x

Where, k is the spring stiffness and x is the displacement:

                                 F_weight = F_spring

                                 19109.88 = k*x

                                 x = 19109.88 / k

We need to assume the spring stiffness we will take k = 160,0000 N/m (trucks suspension systems). The value of the stiffness must be high enough to sustain a load of 1.911 tonnes.

                                 x = 19109.88 / 160,000

                                 x = 0.1194 m ≈ 0.12 m = 12 cm

- A compression of 12 cm seems reasonable for a taptap to carry 1.911 tonnes of load. Hence, the assumption of spring stiffness was reasonable. Hence, the compression of spring is x = 0.12 m.

8 0
3 years ago
Radiation from the Sun The intensity of the radiation from the Sun measured on Earth is 1360 W/m2 and frequency is f = 60 MHz. T
Zina [86]

a) Total power output: 3.845\cdot 10^{26} W

b) The relative percentage change of power output is 1.67%

c) The intensity of the radiation on Mars is 540 W/m^2

Explanation:

a)

The intensity of electromagnetic radiation is given by

I=\frac{P}{A}

where

P is the power output

A is the surface area considered

In this problem, we have

I=1360 W/m^2 is the intensity of the solar radiation at the Earth

The area to be considered is area of a sphere of radius

r=1.5\cdot 10^{11} m (distance Earth-Sun)

Therefore

A=4\pi r^2 = 4 \pi (1.5\cdot 10^{11})^2=2.8\cdot 10^{23}m^2

And now, using the first equation, we can find the total power output of the Sun:

P=IA=(1360)(2.8\cdot 10^{23})=3.845\cdot 10^{26} W

b)

The energy of the solar radiation is directly proportional to its frequency, given the relationship

E=hf

where E is the energy, h is the Planck's constant, f is the frequency.

Also, the power output of the Sun is directly proportional to the energy,

P=\frac{E}{t}

where t is the time.

This means that the power output is proportional to the frequency:

P\propto f

Here the frequency increases by 1 MHz: the original frequency was

f_0 = 60 MHz

so the relative percentage change in frequency is

\frac{\Delta f}{f_0}\cdot 100 = \frac{1}{60}\cdot 100 =1.67\%

And therefore, the power also increases by 1.67 %.

c)

In this second  case, we have to calculate the new power output of the Sun:

P' = P + \frac{1.67}{100}P =1.167P=1.0167(3.845\cdot 10^{26})=3.910\cdot 10^{26} W

Now we want to calculate the intensity of the radiation measured on Mars. Mars is 60% farther from the Sun than the Earth, so its distance from the Sun is

r'=(1+0.60)r=1.60r=1.60(1.5\cdot 10^{11})=2.4\cdot 10^{11}m

Now we can find the radiation intensity with the equation

I=\frac{P}{A}

Where the area is

A=4\pi r'^2 = 4\pi(2.4\cdot 10^{11})^2=7.24\cdot 10^{23} m^2

And substituting,

I=\frac{3.910\cdot 10^{26}}{7.24\cdot 10^{23}}=540 W/m^2

Learn more about electromagnetic radiation:

brainly.com/question/9184100

brainly.com/question/12450147

#LearnwithBrainly

4 0
3 years ago
You need to design a 60.0-Hz ac generator that has a maximum emf of 5200 V. The generator is to contain a 130-turn coil that has
dimaraw [331]

Answer:

B =  0.129 T

Explanation:

Given,

frequency, f = 60 Hz

maximum  emf = 5200 V

Number of turns, N = 130

Area per turn = 0.82 m²

We know,

ω = 2 π f

ω = 2 π x 60 = 376.99 rad/s

now, Magnetic field calculation

B =\dfrac{\epsilon_{max}}{NA\omega}

B =\dfrac{5200}{130\times 0.82\times 376.99}

B =  0.129 T

Hence, the magnetic field is equal to B =  0.129 T

3 0
3 years ago
Do atoms have full outer energy level combine with other atoms
Pavlova-9 [17]
All of the Noble Gases, which are on the right side of the periodic table, have a full outer energy level. The elements that are Noble Gases are the following: <span>Neon Argon Krypton Xenon Radon Ununoctium. 

Hope this helps.</span>
8 0
3 years ago
A resistor is connected in series with an AC source that provides a sinusoidal voltage of v of t is equal to V times cosine of b
nekit [7.7K]
<h2>Answer:</h2>

In circuits, the average power is defined as the average of the instantaneous power  over one period. The instantaneous power can be found as:

p(t)=v(t)i(t)

So the average power is:

P=\frac{1}{T}\intop_{0}^{T}p(t)dt

But:

v(t)=v_{m}cos(\omega t) \\ \\ i(t)=i_{m}cos(\omega t)

So:

P=\frac{1}{T}\intop_{0}^{T}v_{m}cos(\omega t)i_{m}cos(\omega t)dt \\ \\ P=\frac{v_{m}i_{m}}{T}\intop_{0}^{T}cos^{2}(\omega t)dt \\ \\ But: cos^{2}(\omega t)=\frac{1+cos(2\omega t)}{2}

P=\frac{v_{m}i_{m}}{T}\intop_{0}^{T}(\frac{1+cos(2\omega t)}{2} )dt \\\\P=\frac{v_{m}i_{m}}{T}\intop_{0}^{T}[\frac{1}{2}+\frac{cos(2\omega t)}{2}]dt \\\\P=\frac{v_{m}i_{m}}{T}[\frac{1}{2}(t)\right|_0^T +\frac{sin(2\omega t)}{4\omega} \right|_0^T] \\ \\ P=\frac{v_{m}i_{m}}{2T}[(t)\right|_0^T +\frac{sin(2\omega t)}{2\omega} \right|_0^T] \\ \\ P=\frac{v_{m}i_{m}}{2}

In terms of RMS values:

V_{RMS}=V=\frac{v_{m}}{\sqrt{2}} \\ \\ I_{RMS}=I=\frac{i_{m}}{\sqrt{2}} \\ \\ Then: \\ \\ P=VI

7 0
3 years ago
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