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3 years ago

Car 1 of mass m1 is waiting at a traffic light.

Physics

1 answer:

defon3 years ago

7 0

Answer: KE= 1/2 m v^2

KE= 1/2 2500 (0)^2

KE= 0

Explanation: since initial velocity is 0, the KE is 0.

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Your boss wants you to advise him about what shape of wheels to use for his son’s pinewood

Morgarella [4.7K]

Answer:

Ring v² = gh

solid wheel (cylinder) v² = 4/3 gh

Explanation:

Let's use conservation of energy to find the speed of the wheels at the bottom of the hill.

starting point. Point before starting movement

Em₀ = mgh

final point. At the bottom of the hill

Em_f = K = ½ m v² + ½ I w²

energy is conserved

Emo = Em_f

mgh = ½ m v² + ½ I w²

angular and linear velocity are related

v = w r

we substitute

mgh = ½ m v² + ½ I v² / r²

mgh = $\frac{1}{2} \ ( m+ \frac{I}{r^2} ) \ v^2$ ½ (m + I / r²) v²

v² = $\frac{2mgh}{m+ \frac{I}{r^2} }$

the moments of inertia are tabulated

Ring

I = mr²

v² = 2 m g h / (m + m)

v² = gh

solid wheel (cylinder)

I = ½ m r²

v² = 2m gh / (m + m / 2)

v² = 4/3 gh

We can see that due to the difference in the moment of inertia of each body it is different, the solid wheel has more speed when it reaches the lower part of the ramp

4 0

3 years ago

The most narrow region of the electromagnetic spectrum is

Lostsunrise [7]

The answer is A. X rays or it can be visible light but mostly A.

4 0

3 years ago

Consider a taut inextensible string. You shake the end of the string with some frequency, causing a wave to travel down the stri

masha68 [24]

Answer:

Part 1:

Option B is correct (It will remain unchanged).

Part 2:

Option C is correct (It will increase by a factor of √ 2)

Part 3:

Option E is correct (It will be half as fast/long.)

Part 4:

Option C is correct (It will increase by a factor of √ 2.)

Explanation:

Formula we are going to use:

V=f*λ

Where:

V is the speed of Sound

f is the frequency of wave

λ is the wavelength.

The speed of wave , tension and linear density have following relation:

$V=\sqrt{F/\rho}$

Where:

V is the speed of Sound (Initial)

F is the tension in string (Initial)

$\rho$ is the linear density of string (Constant)

Terms:

V' is the new speed

f' is the new frequency

λ' is the wavelength

Solution:

Part 1:

From $V=\sqrt{F/\rho}$ :

Speed of Sound is independent of the frequency of shaking so speed well remain unchanged.

Option B is correct (It will remain unchanged)

Part 2:

If F'=2F then

$V=\sqrt{F/\rho}$

$V'=\sqrt{F'/\rho}\\V'=\sqrt{2F/\rho}\\V'= \sqrt{2} * \sqrt{F/\rho}\\V'=\sqrt{2}V$

Option C is correct (It will increase by a factor of √ 2)

Part 3:

Formula we are going to use:

V=f*λ

Given f'=2f,

Even though frequency is doubled we will keep velocities same. V=V' in order to find the changing wavelength.

V'=f'*λ'

f*λ=f'*λ'

f*λ=2f*λ'

Solving above Equation:

λ'=λ/2

Option E is correct (It will be half as fast/long.)

Part 4:

T'=2T means $V'=\sqrt{2}V$ (From Part 1)

f'=f

Now:

V'=f'*λ'

$\sqrt{2}f*\lambda=f'*\lambda '\\\sqrt{2}f*\lambda=f*\lambda '\\ \lambda '=\sqrt{2}*\lambda$

Option C is correct (It will increase by a factor of √ 2.)

5 0

3 years ago

What is the correct definition for energy?

WINSTONCH [101]

Property of objects which can be transferred to other objects or converted into different forms.

3 0

3 years ago

Read 2 more answers

If the incoming solar radiation is scattered, it __________.

Lina20 [59]

Answer:

The wavelength is longer and warms the atmosphere

Explanation:

Hope it helps sorry it is late

7 0

3 years ago

Read 2 more answers