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3 years ago

Which of the following is the best definition of a physical change?

Physics

2 answers:

Ymorist [56]3 years ago

6 0

Answer:

The answer is C. A change in a substance with no new substances being formed

Explanation:

I did the quiz.

Marina CMI [18]3 years ago

4 0

Answer:

(A) a change in a substance where a new substance is formed.

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How much force must you apply to give the go cart an acceleration of 0.9m/s^2

qaws [65]

It's dependent on the mass. You can fimd the force needed using the formula F = ma. Where F is force, m is mass of the cart and a is the acceleration (0.9m/s^2). The heavier it is the more force you are going to need. Remember unit of force is N

5 0

3 years ago

The maximum speed at which a patch of the surface moves during a vibration is 4.5 m/s . What is the amplitude of the vibration,

frutty [35]

Answer:

a) Angular frequency, w = 0.0184 rad/s

b) Amplitude of vibration = 245 m

Explanation:

a) Angular frequency, w = 2πf

f = 1/T, T = 5.7 minutes = 5.7 × 60 = 342 s

f = 1/342 = 0.00292 Hz or 0.00292/s

w = 2π (0.00292) = 0.0184 rad/s

b) Amplitude of simple harmonic motion,

displacement of simple harmonic motion, x(t) = A cos (wt-Φ)

A = amplitude

v = dx/dt = - Aw (sin (wt - Φ)

Velocity amplitude of simple harmonic motion = Amplitude × angular frequency

Amplitude = (velocity amplitude)/(angular frequency) = 4.5/0.0184 = 245m

Hope this Helps!!!

7 0

3 years ago

A slice of bread contains about 100 kcal. If specific heat of a person were 1.00 kcal/kg·°C, by how many °C would the temperatur

almond37 [142]

Answer:

(c) 1.43°C

Explanation:

If the energy in the bread are converted to heat.

Then, The heat transferred from the bread to person = 100 kcal.

From specific heat capacity,

Q = cmΔT............................ equation 1

Where Q = quantity of heat, m = mass of the person, c = specific heat capacity of the person, Δ = increase in temperature.

Making ΔT the subject the equation 1,

ΔT = Q/cm........................ equation 2

Where Q = 100 kcal, c= 1.00 kcal/kg.°C, m = 70.0 kg

Substituting these values into equation 2,

ΔT = 100/(1×70)

ΔT = 100/70

ΔT = 1.428

ΔT ≈ 1.43°C

The increase in temperature of the body is = 1.43°C

The right option is (c) 1.43°C

5 0

3 years ago

Priscilla is driving her car on a busy street and Harvey passes her on his motorcycle. What will happen to the sound from his mo

LiRa [457]

Answer:

the correct answer is A

Explanation:

This is a doppler effect exercise which is the change in frequency due to the relative movement of the sound source and the observer.

$f' = f_o \ \frac{v+v_o}{v-v_s}$

where v₀ is the speed of the observer and v_s the speed of the source, the signs correspond when the two are closing in

with this expression let's analyze the different answers

A) True. The observed change is in the frequency, in this case the two are moving away, so the expression that describes the phenomenon is

$f'= f_o \ \frac {v-v_o}{ v+v_s}$

In this case, the speed of the source is greater than the speed of the observer, so when the denominator increases faster than the numerator, consequently the frequency must decrease

B) False. The amplitude does not depend on the relative velocity

C) False. The intensity depends on the distance, by or which when increasing the distance the intensity should decrease

D) False. The speed of sound is a constant, if the frequency decreases the wavelength must increase to maintain equality

E) False. The speed of sound depends on the properties of the propagating medium, not on the relative speed of the source and the observer.

Consequently the correct answer is A

4 0

3 years ago

What unit describes thr magnitude, or size of a force?

Bess [88]

N - adica Newtonul.
Sper că team ajutat

5 0

3 years ago

Read 2 more answers