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3 years ago

A box of mass 20kg is pulled up an inclined plane by a force of 285N. Given that the value of

Physics

1 answer:

lorasvet [3.4K]3 years ago

4 0

Answer:

19.6 m/s

Explanation:

The parameters given are:

Mass M = 20 Kg

Force F = 285 N

Angle Ø = 30 degree

Time t = 4 seconds

Coefficient of friction = 0.72

At the plane, the weight of the box will be mgsinØ

Resolving forces at the plane, we will have:

MgsinØ + Fr = F

Where Fr = frictional force.

Fr = F - mgsinØ

Substitute all the parameters into the formula

Fr = 285 - 20 × 9.8 sin30

Fr = 285 - 98

Fr = 187 N

But for the box moving toward the top of the plane,

F - Fr = ma

Where a = V/t

Substitute all the parameters involved into the formula

285 - 187 = 20 ( V/4)

98 = 5V

V = 98/5

V = 19.6 m/s

Therefore, the speed with which the box is moving is 19.6 m/s

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Marysya12 [62]

We can find the force by using the following formula;
N = ma + mg
Fa = ma = 76 x 1.2 = 91.2
Fg = mg = 76 x 9.8 = 744.8
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So, the force is 836 N.

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3 years ago

Which statement best describes the energy changes that occur while a child is riding on a sled down a steep, snow-covered hill?

svp [43]

The answer is C, because they moved from a stand still to down the hill

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4 years ago

What is the density (in kg/m3) of a woman who floats in freshwater with 4.92% of her volume above the surface

kipiarov [429]

Answer:

The density of the woman is 950.8 kg/m³

Explanation:

Given;

fraction of the woman's volume above the surface = 4.92%

then, fraction of the woman's volume below the surface = 100 - 4.92% = 95.08%

the specific gravity of the woman $= \frac{95.08}{100 } = 0.9508$

The density of the woman is calculate as;

$Specific \ gravity \ of \ the \ woman = \frac{Density \ of \ the \ woman }{Density \ of \ fresh \ water }\\\\ Density \ of \ the \ woman = Specific \ gravity \ of \ the \ woman \ \times \ Density \ of \ fresh \ water$

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Density of the woman = 0.9508 x 1000 kg/m³

Density of the woman = 950.8 kg/m³

Therefore, the density of the woman is 950.8 kg/m³

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3 years ago

Julie's psychologist helped her get over her fear of spiders. Which goal of psychology has the phycologist met ?

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<span>The four goals of psychology are: describe observed phenomena, explain them, predict what may occur as a result of them and control behaviour as a result. Julie’s psychologist has helped Julie control her behaviour - her fear response to spiders - so they have met the ‘control behaviour’ goal of psychology.</span>

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3 years ago

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wariber [46]

Answer:

Alburt Bandura

Explanation:

Rosalind has learned to be impulsive and seldom waits for her turn when playing with other children, this trait she has learned from her father, who is also an impulsive man.

The theorist who would most likely suggest that Rosalind has learned to be impulsive from watching her father is Alburt Bandura. Alburt in his famous Bebo Doll experiment confirmed that children learn from the adults behavior in their life.

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3 years ago