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SashulF [63]
3 years ago
10

An 84% efficient single pulley is used to lift a 230 kg piano 3.5 m. How much work must be input?

Physics
1 answer:
Sati [7]3 years ago
3 0

Answer:

35%

Explanation:

win

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Irregular galaxies are very large. True or False?
xenn [34]
It's false i hope this helps :)

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3 years ago
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A flowerpot falls from the ledge of an apartment building. A person in an apartment below, coincidentally holding a stopwatch, n
valkas [14]

Answer

given,

height of window = 4 m

time taken to travel = 1 s

acceleration due to gravity = 9.8 m/s²

s = ut + \dfrac{1}{2}at^2

u = \dfrac{s - \dfrac{1}{2}at^2}{t}

u = \dfrac{4 - \dfrac{1}{2}\times 9.8\times 1^2}{1}

u = -0.905 m/s

initial velocity of ledge v = 0

now,

v² = u² + 2 a s

(-0.905)² = 0 + 2 × 9.8 ×s

s = 0.042 m

6 0
3 years ago
A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. Complete the following statemen
Eva8 [605]

Answer:

Keeping the speed fixed and decreasing the radius by a factor of 4

Explanation:

A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. The centripetal acceleration is given by :

a=\dfrac{v^2}{R}

We need to find how the "centripetal acceleration of the ball can be increased by a factor of 4"

It can be done by keeping the speed fixed and decreasing the radius by a factor of 4 such that,

R' = R/4

New centripetal acceleration will be,

a'=\dfrac{v^2}{R'}

a'=\dfrac{v^2}{R/4}

a'=4\times \dfrac{v^2}{R}

a'=4\times a

So, the centripetal acceleration of the ball can be increased by a factor of 4.

7 0
3 years ago
Which of the following statements about price elasticity of demand is​ true?
STatiana [176]

Answer:

B. The elastic portion of a​ straight-line, downward-sloping demand curve corresponds to the segment above the midpoint.

Explanation:

Elasticity measures the sensitivity of one variable to another. Specifically it is a figure that indicates the percentage variation that a variable will experience in response to a variation of another one percent.

The elasticity of demand measures the reaction of demand when one of the factors that affects it varies.

<u>Elasticity - Price of demand.</u>

easure the sensitivity of the quantity demanded to price variations. It indicates the percentage variation that the quantity demanded of a good will experience if its price rises by 1 percent.

<u> Elastic Demand </u>

The demand quantity is relatively sensitive to price variations, so the total expenditure on the product decreases when the price rises, the price elasticity takes value greater than -∞ but less than -1

7 0
3 years ago
1.what is gravity?(in your own words)
olga_2 [115]

Answer:

1.Gravity is an invisible force that pulls objects toward each other

2.The suns gravity pulls the planet towards the sun which changes the straight line of direction into a curve

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hope it helped:)

8 0
2 years ago
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