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3 years ago

If I drop a feather and a elephant from an equal height in a vacuum which will hit the ground first?

2 answers:

8 0

Whichever one you drop first will hit the ground first. If you drop them simultaneously, and they don't interfere with each other on the way down, then they will hit the ground simultaneously.

attashe74 [19]3 years ago

4 0

They will both hit the ground at the same time, as there is no air resistance in a vacuum, and weight does not determine which object will fall faster even where there is gravity.

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Which of the following correctly shows the chain of energy transfers that create surface currents on the ocean?

Colt1911 [192]

D.
Solar energy is converted to wind energy which then drive surface currents.

8 0

3 years ago

According to one set of measurements, the tensile strength of hair is 196 MPa , which produces a maximum strain of 0.380 in the

slega [8]

Answer:

(a). The magnitude of the force is 0.38416 N.

(b). The original length is 0.0869 m.

Explanation:

Given that,

Tensile strength = 196 MPa

Maximum strain = 0.380

Diameter = 50.0 μm

Length = 12.0 cm

We need to calculate the area

Using formula of area

$A=\dfrac{\pi}{4}\times d^2$

Put the value into the formula

$A=\dfrac{\pi}{4}\times(50.0\times10^{-6})^2$

$A=1.96\times10^{-9}\ m^2$

We need to calculate the magnitude of the force

Using formula of force

$F=\sigma A$

Put the value into the formula

$F=196\times10^{6}\times1.96\times10^{-9}$

$F=0.38416\ N$

(b). If the length of a strand of the hair is 12.0 cm at its breaking point

We need to calculate the unstressed length

Using formula of strain

$strain=\dfrac{\Delta l}{l_{0}}$

$\Delta l=strain\times l_{0}$

Put the value into the formula

$\Delta l=0.380\times l_{0}$

Length after expansion is 12 cm

We need to calculate the original length

Using formula of length

$l=l_{0}+\Delta l$

Put the value into the formula

$I=l_{0}+0.380\times l_{0}$

$l=1.38l_{0}$

$l_{0}=\dfrac{l}{1.38}$

$l_{0}=\dfrac{12\times10^{-2}}{1.38}$

$l_{0}=0.0869\ m$

Hence, (a). The magnitude of the force is 0.38416 N.

(b). The original length is 0.0869 m.

4 0

3 years ago

-What can you say about the snowboarder’s kinetic energy as he moves?

Damm [24]

Answer:

His kinetic energy increases, potential energy decreases

The sum of kinetic and potential energy is a constant at any instant before he comes to rest.

Explanation:

Snowboarder is starting from a height and moving to the down direction. As he moves down his velocity increases, we know that kinetic energy is given by the expression $\frac{1}{2} mv^2$ , so as he moves his kinetic energy increases.

When the snowboarder is starting his potential energy is maximum(Potential energy = mgh), as he comes down his potential energy decreases.

Based on this we can conclude that the sum of potential energy and kinetic energy is a constant at any instant for a snowboarder before he comes to rest.

mgh+ $\frac{1}{2} mv^2$ = Constant

7 0

3 years ago

Though some self-report error may exist, surveys/interviews are useful in that they allow researchers to collect large amounts o

Leokris [45]

Definitely true, surveys and interviews aren’t flawless but you can collect lots of data from them

4 0

2 years ago

A race car accelerates from 0 m/s ro 30 m/s with a displacement of 45 what is it acceleration

Minchanka [31]

Hdghehwhevevwgwhhwvsvsvsiosjwbwbwhshbshs

6 0

3 years ago