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3 years ago

What does convection mean

1 answer:

4 0

Convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat

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a singer emits a note of frequency 200hz. calculate the wavelength of the note. (speed of sound in air= 340m/s). please help me

Novay_Z [31]

Wavelength = Speed / Frequency = 340/200= 1.7m

8 0

3 years ago

Which velocity graph shows the car moving toward the right (away from the origin) at a steady (constant) velocity?

slega [8]

Explanation:

$\text{Velocity is defined as the average displacement per unit time.}$

$\text{Since the car is moving at a steady velocity, the velocity does not change over time, it shows a horizontal line on the }v-t\text{ graph}$

$\text{Therefore, only option 2,5,8 matches this requirement.}$

$\text{Since the car is moving to the right, which is defined as the positive direction in this question, the velocity (}v\text{) is also positive.}$

$\text{Therefore, only option 5 is correct.}$

6 0

3 years ago

The objective lens of a certain refracting telescope has a diameter of 63.5 cm. The telescope is mounted in a satellite that orb

Ostrovityanka [42]

Answer:

0.255 m

Explanation:

We are given that

Diameter=d=63.5 cm= $63.5\times 10^{-2} m$

$1 cm=10^{-2} m$

L=265 km = $265\times 1000=265000 m$

Wavelength, $\lambda=500nm=500\times 10^{-9} m$

$1nm=10^{-9} m$

We have to find the minimum distance between two objects on the ground if their images are to be resolved by this lens.

$sin\theta=1.22\frac{\lambda}{d}$

$sin\theta=\frac{1.22\times 500\times 10^{-9}}{63.5\times 10^{-2}}$

$sin\theta=\approx \theta=9.606\times 10^{-7} rad$

$\frac{y}{L}=tan\theta\approx \theta$

$y=L\theta=265000\times 9.606\times 10^{-7}=0.255 m$

5 0

3 years ago

In the laboratory, a ball is dropped onto a force-sensing platform several times, each time hitting a different surface (foam, f

NeX [460]

Answer:

Graphing the momentum against the change in moment yields a linear relationship.

Explanation:

This is an impulse experiment,

I = ∫ F .dt

where the force and time of the collision are measured, therefore if we assume an average force the integral reduces to

I = F t

Furthermore, the momentum is equal to the change in moment of the ball, this change in moment can be found using the energy relations measuring the height of the ball and calculating its speed, in the two intervals for the descent and for the exit, possibly the heights are different so the moment change is different from zero.

Starting point. Higher

Em₀ = U = mgh

Lower end point, just before hitting the scale

$Em_{f}$ = K = ½ m v²

in the path in the air there is no friction

Em₀ = Em_{f}

m g h = ½ m v²

v = $\sqrt{2gh}$

this height is different for the descent and ascent of the ball, so we have two moments

Δp = $p_{f}$ - p₀

Δp = m (v_{f} -v₀)

therefore we have the relationship

I = Δp

Graphing the momentum against the change in moment yields a linear relationship.

5 0

3 years ago

2. Without changing the mass or height, what else do you think you could do to design a system in which GPE and KE values are mo

Andru [333]

Answer:

jgvvjlvcgkgc

Explanation:

5 0

3 years ago