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3 years ago

Which of the following quantities is a vector?

Physics

2 answers:

love history [14]3 years ago

5 0

Answer:

Explanation:

vectors have direction!

Elanso [62]3 years ago

3 0

The answer is D hope this helps

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A 480 g peregrine falcon reaches a speed of 69 m/s in a vertical dive called a stoop. If we assume that the falcon speeds up und

LiRa [457]

Answer:

The minimun height is 242 [m]

Explanation:

We can solve this problem by using the principle of energy conservation, where potential energy becomes kinetic energy. We will take the point where the Falcon reaches the speed of 69 (m/s), as the point where the potential energy is zero, i.e. it will be the reference point.

At the reference point all potential energy has been transformed into kinetic energy, therefore the kinetic energy can be calculated.

$E_{k}=0.5*m*v^{2} \\ where:\\v = velocity = 69 [m/s]\\m = mass = 480[g] = 0.480[kg]\\E_{k} = kinetic energy [J]\\E_{k} =0.5*0.48*(69)^{2} \\E_{k} =1142.64[J]$

Now we can calculate the elevation with respect to the reference point using the definition of the potential energy.

$E_{p}=m*g*h\\ E_{p}=E_{k} \\therefore\\h= E_{p}/(m*g)\\h= 1142.64/(.48*9.81)\\h=242[m]$

4 0

3 years ago

A rock band playing an outdoor concert produces sound at 120 dB 5.0 m away from their single working loudspeaker. What is the so

joja [24]

ANSWER:100dB

from the sound intensity level,the sound intensity is calculated as:

$\beta$ ₁= $\beta$ =(10dB)㏒₁₀(l₁/l₀)

inserting numbers:

120dB=(10dB)㏒₁₀[l₁/10⁻¹²W/m⁸] or 12=㏒₁₀[l₁/(10⁻¹²)W/m²

Getting the antilog of both sides and obtain 10¹²=l₁(10⁻¹²W/m²)which

can be used to solve for l₁ and get

l₁=(10⁻¹²W/m²)(10¹²)=1 W/m²

since the sound intensity is related to the power and that the power does not change,the sound intensity at any other point can be solved.Plugging-in

ᵃ = 4πr²,into P=l₁ₐ₁=l₂ₐ₂ and get:

l₂=l₁(r₁/r₂)² =(1W/m²)(5/35) =2.04×10⁻²W/m²

since we know the sound intensity at the sound point 2r,the sound intensity level at the point can be solved.We have:

$\beta$ ₂= $\beta$ =(10dB)㏒₁₀(l₂/l₀)=(10dB)㏒₁₀(2.04×10⁻²/1×10⁻²)

$\beta$ ₂=(10dB)㏒₁₀(2.04×10¹⁰)

$\beta$ =(10dB)[㏒₁₀(2.04)+㏒₁₀(10¹⁰)]=10dB[0.32+10]=103dB=100dB

3 0

4 years ago

Black holes are:

agasfer [191]

Answer to the question provided is A

4 0

4 years ago

Read 2 more answers

A lens with f = +11cm is paired with a lens with f = −25cm. What is the focal length of the combination?

Zepler [3.9K]

Answer:

19.642 cm

Explanation:

f₁ = Focal length of first lens = 11 cm

f₂ = Focal length of second lens = -25 cm

Combined focal length formula

$\frac{1}{f}=\frac{1}{f_1}+\frac{1}{f_2}\\\Rightarrow \frac{1}{f}=\frac{1}{11}+\frac{1}{-25}\\\Rightarrow \frac{1}{f}=\frac{14}{275}\\\Rightarrow f=\frac{275}{14}\\\Rightarrow f=19.642\ cm$

Combined focal length is 19.642 cm

5 0

3 years ago

The force of a moving object is called momentum. The momentum of an object is proportional to its weight and speed. The more mom

dexar [7]

The force that a moving object exerts on another object upon colliding with it is rather the change in momentum divided by the amount of time elapsed during the collision.

F = Δp/Δt

F = force, Δp = change in momentum, Δt = elapsed time

Usually we say momentum is proportional to mass instead of saying momentum is proportional to weight. But sure, for two objects on the same planet, greater weight implies greater mass. Momentum is the product of mass and velocity:

p = mv

p = momentum, m = mass, v = velocity

So we have two identical cars on the same planet with one car traveling 30mph faster than the other. Let's say they both collide with a tree, both coming to a rest, and the collisions take the same amount of time to happen. The faster car loses a greater amount of momentum over the same amount of time, therefore delivering a greater force.

Choice B

4 0

3 years ago