Help me guys plzzzzzzzzz

A crate falls from an airplane flying horizontally at an altitude of 2,000 m.

Hatshy [7]

Answer:

20.2 seconds

Explanation:

The airplane (and therefore the crate) initially has no vertical velocity, so v₀ = 0 m/s.

The crate is in free fall, so a = -9.8 m/s².

The crate falls downward, so Δx = -2000 m.

Find: t, the time it takes for the crate to land.

Δx = v₀ t + ½ at²

-2000 m = (0 m/s) t + ½ (-9.8 m/s²) t²

t = 20.2 s

It takes 20.2 seconds for the crate to land.

7 0

4 years ago

2. Which of the following is a true statement.

lorasvet [3.4K]

Answer:

Sound travels slower than light

Explanation:

Sound travels at around 1/3 km per second, while light travels around 300,000 km per second.

Also, this is the reason you see the lightning before you hear the thunder.

I hope this helped.

5 0

3 years ago

Read 2 more answers

A newspaper delivery boy throws a newspaper onto a balcony 1.25 m above the

velikii [3]

Answer:

(a) 3.22 m

(b) The vertical velocity, $v_y$ , at maximum height is 0 m/s, the horizontal velocity, vₓ, is 12.72 m/s

(c) The acceleration at maximum height = g = 9.81 m/s²

(d) The time it takes for the paper to reach the balcony is 1.212 seconds

(e) The horizontal range, of the paper is 15.42 m.

Explanation:

(a) Given that we re given a projectile motion, we have the following governing equations;

y = y₀ + v₀·sin(θ₀)·t - 0.5×g·t²

$v_y$ = v₀·sin(θ₀) - g·t

Where:

y = Height of the paper

y₀ = Initial height of the paper = Ground level = 0

v₀ = Inititial velocity of the paper = 15.0 m/s

θ₀ = Angle in which the paper is thrown = 32° above the horizontal

g = Acceleration due to gravity = 9.81 m/s²

t = Time taken to reach the height h

$v_y$ = Vertical velocity of the paper

At maximum height, $v_y$ = 0, therefore;

$v_y$ = v₀·sin(θ₀)·t - g·t = 0

v₀·sin(θ₀) = g·t

t = v₀·sin(θ₀)/g = 15×sin(32°)/9.81 = 0.81 seconds

y = y₀ + v₀·sin(θ₀)·t - 0.5×g·t² = 0 + 15×sin(32°)×0.81-0.5×9.81×0.81² = 3.22 m

(b) The vertical velocity, $v_y$ , at maximum height = 0 m/s, the horizontal velocity, vₓ, = 15×cos(32°) = 12.72 m/s

(c) The acceleration at maximum height = g = 9.81 m/s²

(d) The time it takes to maximum height = 0.81 seconds

The time the paper will take to fall to 1.25 m above the ground, which is 3.22 - 1.25 = 1.97 meters below maximum height is therefore given as follows;

y = y₀ + v₀·sin(θ₀)·t - 0.5×g·t²

Where:

v₀ = 0 m/s at maximum height

y = -1.97 m downward motion

y₀ = 0 starting from maximum height downwards

1.97 = 0 + 0·sin(θ₀)·t - 0.5×9.81×t²

-1.97 = - 0.5×9.81×t²

t = (-1.97)/(-0.5*9.81) = 0.402 seconds

The time the paper will take to fall to 1.25 m above the ground = 0.81+0.402 = 1.212 seconds

Therefore, the time it takes for the paper to reach the balcony = 1.212 seconds

(e) The horizontal range, x, is given by the relation;

x = x₀ + v₀·cos(θ₀)· $t_{tot}$

x₀ = Starting point of throwing the paper = 0

$t_{tot}$ = Total time of flight of the paper

∴ x = x₀ + v₀·cos(θ₀)· $t_{tot}$ = 0 + 15×cos(32°)×1.212 = 15.42 m

The horizontal range, of the paper = 15.42 m.

4 0

4 years ago

What is an example of a mechanical noise?

faltersainse [42]

Resonance:
The resounding recurrence is the recurrence at which a bit of metal, plastic or whatever else swings/vibrates with minimal measure of vitality input. Think about a man on a play area swing. You realize that it requires next to no push to keep the individual swinging. The recurrence at which they swing forward and backward is their full recurrence. In the event that you endeavor to influence them to swing speedier or slower, it will take altogether more vitality.

Resonating Panels:
This kind of clamor is caused when the bass notes are an indistinguishable recurrence from the thunderous recurrence of a metal or plastic board. To stop or decrease the commotion related with this kind of issue, you can do two or three things.

Rattling:
This sort of commotion would be caused when 2 bits of metal, plastic, whatever... are sufficiently close to hammer into each other when they resound. This is most likely best illuminated by filling the hole between the two vibrating parts with silicone sealant or shut cell froth climate stripping. The climate stripping is a superior arrangement in places like behind the tag. On the off chance that you have a tag outline, you can get some truly thin climate stripping and put between the casing and the plate.

4 0

3 years ago

Are there any difference betwn supersonic planes and concorde planes

malfutka [58]

<u>Answer</u>:

Yes, there are differences between supersonic planes and concorde planes

<u>Explanation</u>:

The supersonic planes moves faster than the speed of sound. But these flights are banned because it is economically non-starter. It has more loud sound equivalent to the explosion. The banned was elevated in 2003, due to new aviation law. The concords travel twice the speed of sound. This planes holds the record for the fastest planes but seen to be fleet long back i.e. in 2003. These were banned when a fatal crash had been reported. And now are only found in the museums.

7 0

3 years ago