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3 years ago

Can someone please help me ASAP!

Physics

1 answer:

Artist 52 [7]3 years ago

3 0

I’m not 100% sure but i think it’s A because if you divide the speed by the time you get 2 and also all the other answer choices don’t make any sense!

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An escalator carries you from one level to the next in an airport terminal. The upper level is 4.4m above the lower level, and t

horrorfan [7]

Answer:

Part a)

$W = 2716.5 J$

Part B)

$W = -2716.5 J$

Explanation:

Part A)

While escalator is moving up work done to move the person upwards is given as

$W = mgh$

here we know that

m = 63 kg

h = 4.4 m

now we have

$W = 63 \times 9.8 \times 4.4$

$W = 2716.5 J$

Part B)

Work done while we move from up to down

So we have

$W = - mgh$

so we have

$W = -2716.5 J$

6 0

3 years ago

After travelling 4.0 km, the train reaches its maximum speed. it continues at this constant speed on the next section of the tra

lozanna [386]

Answer:

toward the center of the circular curve

Explanation:

An object will follow a circular path at constant speed if and only if its net acceleration is constant and directed toward the center of the curved path.

The result force is directed toward the center of the circle.

_____

<em>Additional comment</em>

If any part of the result force is in the direction of motion, the speed will not be constant. If the center-directed force is not constant, the path will not be circular.

5 0

2 years ago

What was the near extinction of many birds was caused by

Nat2105 [25]

I believe the use of DDT

5 0

3 years ago

In which part of the ear are the vibrations occurring in a gas, liquid, and solid?

UkoKoshka [18]

Answer:

eardrum is the correct answer

hope this helps ❤️

Explanation:

Sound waves enter the ear canal and cause the eardrum to vibrate. Three small bones transmit these vibrations to the cochlea. This produces electrical signals which pass through the auditory nerve to the brain, where they are interpreted as sound.

5 0

3 years ago

A ball of mass m is thrown straight upward from ground level at speed v0. At the same instant, at a distance D above the ground,

n200080 [17]

Answer:

a. $t = \frac{v_{0} +/- \sqrt{v_{0} ^{2} - gD} }{g}$ b. D = v₀²/2g

Explanation:

Here is the complete question

A ball is thrown straight up from the ground with speed v₀ . At the same instant, a second ball is dropped from rest from a height D , directly above the point where the first ball was thrown upward. There is no air resistance

Find the time at which the two balls collide.

Express your answer in terms of the variables D ,v₀ , and appropriate constants..

t = ?!

Part B

Find the value of D in terms of v₀ and g so that at the instant when the balls collide, the first ball is at the highest point of its motion.

Express your answer in terms of the variables v₀ and g .

D =?!

Solution

The distance moved by the ball dropped from distance,D with velocity v₀, H₁ = D - (v₀t - gt²/2) = D + v₀t + gt²/2.

The distance moved by the ball thrown straight upward with velocity v₀ is H₂ = v₀t - gt²/2.

The two balls collide when their vertical distances are equal. That is H₁ = H₂

So, D - v₀t + gt²/2 = v₀t - gt²/2

Collecting like terms

D + gt²/2 + gt²/2 = v₀t + v₀t

D +gt² = 2v₀t

gt² - 2v₀t + D = 0.

Using the quadratic formula,

$t = \frac{-(-2v_{0} ) +/- \sqrt{(-2v_{0} )^{2} - 4 X g XD} }{2g} = \frac{2v_{0} +/- \sqrt{4v_{0} ^{2} - 4gD} }{2g} = \frac{v_{0} +/- \sqrt{v_{0} ^{2} - gD} }{g}$

B. At its highest point, the velocity of the first ball, v = 0. Using v² = u² - 2gs where s = highest point of first ball when they collide and u = v₀.

0 = v₀² - 2gs

s = v₀²/2g.

Also, the time it takes the first ball to reach its highest point is gotten from v = u - gt. At highest point, v = 0 and u = v₀. So,

0 = v₀ - gt₀

t₀ = v₀/g

Also H = s₁ + s where s₁ = distance moved by second ball in time t₀ for collision = v₀t₀ - gt₀²/2.

So, H = v₀t₀ - gt₀²/2 + v₀²/2g = v₀(v₀/g) - g(v₀/g)²/2 + v₀²/2g = v₀²/2g - v₀²/2g + v₀²/2g = v₀²/2g

6 0

3 years ago