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4 years ago

9

PLEASE HELP ITS DUE IN 30 minutes!!! which two statements explain why a student standing at the top of a step stool doesnt move

downwards

2 answers:

Lesechka [4]4 years ago

7 0

Answer:

i think it is c and b

Explanation:

Svetach [21]4 years ago

6 0

Answer:

The correct answer is option <em><u>b</u></em> and <em><u>c</u></em>.

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Which of the following objects is the most likely to be magnetic?

Oksanka [162]

An iron pot is mostly magnetic

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3 years ago

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In each case, lifting or pushing, why must you exert a force to move the object? Q1-2: How much more effort is required to lift

musickatia [10]

Answer:

Newton's first law applies. An object at rest will stay that way until a force is applied.
Any amount of effort can be applied to any amount of mass (in the ideal case). The question is not sufficiently specific.

Explanation:

A force is required to move an object because the object will stay at rest until a force is applied.

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The effort required to lift or push two masses instead of one depends on the desired effect. For the same kinetic energy, no more effort is required. For the same momentum, half the effort is required for two masses. For the same velocity, double the effort is required.

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3 years ago

A 100-kg astronaut is floating in outer space. If the astronaut throws a 2-kilogram wrench at a speed of 10 meters per second, w

sergey [27]

Since Astronaut and wrench system is isolated in the space and there is no external force on it

So here momentum of the system will remain conserved

so here we can say

$m_1v_{1i} + m_2v_{2i} = m_1v_{1f} + m_2v_{2f}$

initially both are at rest

so here plug in all values

$0 = 100 v_{1f} + 2\times 10$

$v_{1f} = -0.20 m/s$

so here the astronaut will move in opposite direction and its speed will be equal to 0.20 m/s

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3 years ago

(b) The density of aluminum is 2.70 g/cm3. The thickness of a rectangular sheet of aluminum foil varies

vekshin1

Answer:

(i) $22.48 cm^3$

(ii) $1.5 mm$

Explanation:

Let t be the average thickness of the sheet.

Given that:

Density of the aluminum sheet is $2.70 g/cm^3$

Mass of sheet = 60.7 g

Length of sheet = 50.0 cm

Width of sheet = 30.0 cm

(i) Using, Density=Mass/Volume

$\Rightarrow \text{Volume}=\frac{\text{Mass}}{\text{Density}}$

$\Rightarrow \text{Volume}=\frac{60.7}{2.7}=22.48 cm^3$

Hence, the volume of the sheet is $22.48 cm^3$ .

(ii) Now, as this aluminum sheet is in the shape of a cuboid, so the volume of the sheet is

$\text{Volume}=\text{Length}\times\text{Width}\times\text{Thickness}$

$\Rightarrow 22.48=50\times 30 \times w$

$\Rightarrow w=\frac{22.48}{50\times 30}=0.015 cm$

Hence, the average thickness of the sheet is $1.5 mm$ .

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4 years ago

The picture to the right shows which wave behavior?

kifflom [539]

Answer:

It is refraction

Explanation:

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3 years ago

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