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4 years ago

Power is expressed in ________?

Physics

1 answer:

Anna [14]4 years ago

6 0

Answer:

(B) Joules per second

Explanation:

Power is the amount of work done per unit of time. Since work is measured in Joules, the SI unit of power is Joules per second (J/s), or Watts (W).

Of course, the cooler unit of power is the Horsepower (hp), originally introduced by James Watt himself, using which people nowadays still boast about their favorite car's "strength."

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The human ear canal is about 2.6 cm long and can be regarded as a tube open at one end and closed at the eardrum. What is the fu

Ugo [173]

Answer:

f = v/λ

= v/4*L

= 343 / 4 (0.026)

= 3120 Hz

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3 years ago

Read 2 more answers

Explain why it is better to jump and land with bent knees rather than straight legs? Use key physics vocabulary.

BigorU [14]

Answer:

Bent knees

Explanation:

Depending the height your jumping from, if you were jumping from a high structure it's best if you jump and land on knees so you dont sprang your ankles from jumping and landing on your straight legs, you could even pull a muscle if you land on straight legs.

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3 years ago

In space, there is no friction. Without the force of friction, satellites and other moving objects will continue moving at the s

Yakvenalex [24]

Answer:

Newton's first law

Explanation:

it says that an object will continue to be at rest or keep moving till any external for is applied to it to make it move or stop respectively.

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3 years ago

In astronomy, distances are often expressed in light-years. One light-year is the distance traveled by light in one year. If the

amid [387]

Answer:

dd=4.3 ly=4.3 •9.46•10°15 m=4.1 10°16m.

Explanation:

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2 years ago

An object is propelled straight up from ground level with an initial velocity of 48 feet per second. Its height at time t is mod

Ket [755]

Answer:

Explanation:

For a. its max height and when it occurs. First the max height. That's a y-dimension thing, and in the y-dimension we have this info:

v₀ = 48 ft/s

a = -32 ft/s/s

v = 0 (the max height of an object occurs when the final velocity of the object is 0). Use the following equation for this part of the problem:

v² = v₀² + 2aΔx and filling in:

$0=48^2+2(-32)$ Δx and

0 = 2300 - 64Δx and

-2300 = -64Δs so

Δx = 36 feet.

Now for the time it takes to get to this max height. Final velocity is still 0 here, but the equation is a different one for this part of the problem. Use:

v = v₀ + at and filling in:

0 = 48 - 32t and

-48 = -32t so

t = 1.5 sec. That's part a. Onto part b:

The object hits the ground when its displacement, Δx, is 0. Use this equation for this problem:

Δx = v₀t + $\frac{1}{2}at^2$ and filling in:

$0=48t+\frac{1}{2}(-32)t^2$ and

$0=48t-16t^2$ and

0 = 16t(3 - t) so

t = 0 and t = 3. t = 0 is before the object is propelled, so it makes sense that at 0 seconds, the object was still on the ground, right? Then at 3 seconds, it's back on the ground. (Isn't math just perfectly, beautifully sensible!?) Now onto part c:

We are looking for the time interval when the object is >32 feet. So we use the same equation we just used, but with an inequality instead of an equals sign:

$48t+\frac{1}{2}(-32)t^2 >32$ and get everything on one side and factor it again:

$-16t^2+48t-32>0$ and we find that

1 < t < 2 so the time interval is between 1 and 2 seconds that the object is over 32 feet in the air.

8 0

3 years ago