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2 years ago

A physics teacher performed a demonstration for a science class by pulling a crate across the floor

Physics

1 answer:

nika2105 [10]2 years ago

3 0

Answer:

An opposing force caused by friction produced a lower acceleration than calculated.

Explanation:

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At left A red ball in a box with arrows pointing away from the ball in all directions. In the middle, a blue ball in a box with

MAVERICK [17]

Answer:

first one is b 2nd one is a 3rd is c and the 4th one is c also

Explanation: have a nice day

6 0

1 year ago

Read 2 more answers

A 90 kg painter is standing on a horizontal wooden scaffolding of length 10 m, which is supported on each end by a rope. The pai

RSB [31]

Explanation:

For equilibrium, $\sum M = 0$ .

So, $8 m \times mg - (10 m) T_{1}$ = 0

$T_{1} = \frac{8 \times mg}{10}$

= $\frac{8 \times 90 \times 9.8}{10}$

= 705.6 N

Also, for equilibrium $\sum F_{y}$ = 0

$T_{1} + T_{2} - mg$ = 0

or, $T_{2} = mg - T_{1}$

= $90 \times 9.8 - 705.6$

= 176.4 N

Thus, we can conclude that the tension in the first rope is 176.4 N.

8 0

3 years ago

200 kW of solar radiation is shining on a 300 m^2 parking lot. What is the insulation on the parking lot?

ale4655 [162]

That's "insolation" ... not "insulation".

'Insolation' is simply the intensity of solar radiation over some area.

If 200 kW of radiation is shining on 300 m² of area, then the insolation is

(200 kW) / (300 m²) = (666 and 2/3) watt/m² .

Note that this is the intensity of the incident radiation. It doesn't say anything
about how much soaks in or how much bounces off.

Wait !
I just looked back at the choices, and realized that I didn't answer the question
at all. I have no idea what "1 sun" means. Forgive me. I have stolen your
points, and I am filled with remorse.

Wait again !
I found it, through literally several seconds of online research.

1 sun = 1 kW/m².

So 2/3 of a kW per m² = 2/3 of 1 sun

That's between 0.5 sun and 1.0 sun.

I feel better now, and plus, I learned something.

7 0

3 years ago

Which statement correctly describes the relationship between frequency and wavelength?

Len [333]

The relationship between the frequency and wavelength of a wave is given by the equation:

v=λf, where v is the velocity of the wave, λ is the wavelength and f is the frequency.

If we divide the equation by f we get:

λ=v/f

From here we see that the wavelength and frequency are inversely proportional. So as the frequency increases the wavelength decreases.

So the second statement is true: As the frequency of a wave increases, the shorter the wavelength is.

3 0

2 years ago

Read 2 more answers

You are throwing a stone straight-up in the absence of air friction. The stone is caught at the same height from which it was th

balu736 [363]

Answer:

A. True

Explanation:

When a stone is thrown straight-up, it has an initial velocity which decreases gradually as the stone move to maximum height due to constant acceleration due to gravity acting downward on the stone, at the maximum height the final velocity of the stone is zero. As the stone descends the velocity starts to increase and becomes maximum before it hits the ground.

Height of the motion is given by;

$H = \frac{u^2}{2g}$

g is acceleration due to gravity which is constant

H is height traveled

u is the speed of throw, which determines the value of height traveled.

Therefore, when the stone is caught at the same height from which it was thrown in the absence of air resistance, the speed of the stone when thrown will be equal to the speed when caught.

7 0

2 years ago