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3 years ago

The perimeter of a rectangle is 66 feet. Find its dimensions assuming that its length is 9 feet less than twice its width.

Physics

1 answer:

Nesterboy [21]3 years ago

8 0

Answer:

Length = 19 feet

Width = 14 feet

Explanation:

The perimeter, P, of a rectangle is given by

$P=2(l+w)$

where l is the length and w is the width.

From the question, the length is 9 feet less than twice the width.

$l=2w-9$

Substitute this in the equation for the perimeter.

$P=2(2w-9+w)$

$P=2(3w-9)$

$66=2(3w-9)$

$33=3(w-3)$

$11=w-3$

$w=14$

Substitute for this in the equation for l.

$l=2w-9=2\times14-9=28-9=19$

Hence, the length is 19 feet and the width is 14 feet.

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Taya2010 [7]

Answer:

VB − VA = g tAB & (VA + VB)/2 = h / tAB

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2 years ago

The atomic mass of gold is 0.197 kg/mole. how many moles are in 0.566 kg of gold.

iogann1982 [59]

Explanation:

0.566kg *(1mol/0.197 kg)= 2.87 mol gold

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2 years ago

Read 2 more answers

The tow spring on a car has a spring constant of 3,086 N / m and is initially stretched 18.00 cm by a 100.0 kg college student o

sdas [7]

Answer:

The velocity of the skateboard is 0.774 m/s.

Explanation:

Given that,

The spring constant of the spring, k = 3086 N/m

The spring is stretched 18 cm or 0.18 m

Mass of the student, m = 100 kg

Potential energy of the spring, $P_f=20\ J$

To find,

The velocity of the car.

Solution,

It is a case of conservation of energy. The total energy of the system remains conserved. So,

$P_i=K_f+P_f$

$\dfrac{1}{2}kx^2=\dfrac{1}{2}mv^2+20$

$\dfrac{1}{2}\times 3086\times (0.18)^2=\dfrac{1}{2}mv^2+20$

$50-20=\dfrac{1}{2}mv^2$

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$v=\sqrt{\dfrac{60}{100}}$

v = 0.774 m/s

So, the velocity of the skateboard is 0.774 m/s.

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3 years ago

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2 years ago

If a substance is found to be reactive flammable soluble and explosive what observation is also a physical property

Ainat [17]

Answer:

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Explanation:

Chemical properties only manifest when a chemical reaction occurs. Being reactive, flammable and explosive are chemical properties, because they involve chemical reactions: the substances are changed; the chemical bonds of some substances, called reactants, are broken, and the chemical bonds are created, forming other substances, called products.

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