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3 years ago

A weightlifter raises a 200-kg barbell through a height of 2 m in 2.2 s. the average power he develops during the lift is

2 answers:

4 0

Power is calculated as work per unit time, and work in turn is calculated as force multiplied by distance. In this case, the force required is equivalent to the weight of the barbell multiplied by acceleration due to gravity.
P = W/t = Fd/t = mgd/t = (200 kg)(9.81 m/s^2)(2 m)/2.2 s = 1783.64 Watts.

Liula [17]3 years ago

4 0

Answer:

Power, P = 1781.81 watts

Explanation:

It is given that,

Mass of the barbell, m = 200 kg

It is lifted to a height of, h = 2 m

Time taken, t = 2.2 s

We need to find the develops during the lift. We know that the pwer developed by an object is equal to the rate of doing work. Mathematically, it is given by :

$P=\dfrac{W}{t}$

$P=\dfrac{mgh}{t}$

$P=\dfrac{200\times 9.8\times 2}{2.2}$

P = 1781.81 watts

So, the average power developed during the lift is 1781.81 watts. Hence, this is the required solution.

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Does the planet exert a torque on the meteoroid with respect to the center of mass of the planet? Why or why not?

ra1l [238]

Answer:

yes

Explanation:

because the planet exerts a centripetal force on the meteorold

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2 years ago

A cubical surface surrounds a point charge q . Describe what happens to the total flux through the surface if (c) the surface is

valentina_108 [34]

Answer:

Gauss law states that the electric flux is defined as the electric field multiplied by the area of the surface in a plane perpendicular to the field.

Explanation:

Mathematically,

Φ=Q ϵo

Where;

Q is enclosed charge

ϵo is the permittivity of the free space

According to Gauss law, which states that the electric flux is defined as the electric field multiplied by the area of the surface in a plane perpendicular to the field.

Φ=Q ϵo

Where;

Q is enclosed charge

ϵo is the permittivity of the free space

If the cube is transformed into a sphere the total flux in the electric field remains unchanged or remains the same. This is because the gaussian law does not postulate that electric flux is dependent on the object in a plane. Hence, the transformation of the cube to a sphere does not affect the electric flux generated in the field.

To learn more about how the total flux through a sphere relates to the surface change, click brainly.com/question/4362789

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3 0

1 year ago

The scientific method is a process by which scientists: prove theories to be known facts gain confidence in theories by failing

mixer [17]

Answer:

The scientific method is the process by which scientists gain confidence in theories by failing to prove them wrong.

Explanation:

Scientific method is a step by step process of creating and carrying out experiments. These processes to be performed are derived from logical and rational application of knowledge concerning a particular subject matter. Through these processes, scientists reach a conclusion about the world, these makes them confident in their findings.

The steps involved in scientific method include:

Observation: it is the first step. It enables you organise in your mind how you want the experiment to.

HYPOTHESIS is the result you imagine you'll find.

PREDICTION is how you think about the scientific idea- It solely relies on the hypothesis made.

EXPERIMENT is used to test your hypothesis. It is the tool designed to check if your idea is right or wrong.

CONCLUSION is the final step. It is the result gotten from the experiment. It can approve the hypothesis or reject the hypothesis.

A theory is formed when hypothesis has been tested to be true by many scientists. Hence scientists gain confidence in theories when the scientific method is approved.

A scientific theory is a well-approved explanation of an aspect of the natural world. The approval is based on thoroughly confirmed hypothesis and experiments carried out by many scientists.

5 0

3 years ago

Strictly speaking, will a penny be slightly more massive if it has a negative charge or a positive charge? discuss.

Alex_Xolod [135]

<span>A negatively charged penny is one with extra electrons, which would increase its mass ever so slightly compared to a positively charged penny, or one with a lack of electrons.</span>

5 0

3 years ago

How much time will have passed by the time a sample of an isotope has decayed to 6.25% of its original mass if the half-life is

aleksandrvk [35]

Answer:

60 days.

Explanation:

Let the original mass (N₀) = 1 g

Amount remaining (N) = 6.25% of its original mass

= 6.25% × 1

= 6.25/100 × 1

= 0.0625 g

Half life (t½) = 15 days

Time (t) =?

Next, we shall determine the rate of decay. This can be obtained as follow:

Decay constant (K) = 0.693/ half life

K = 0.693 / t½

Half life (t½) = 15 days

Decay constant (K) =?

K = 0.693 / t½

K = 0.693 / 15

K = 0.0462 / day

Finally, we shall determine the time taken for the sample of the isotope to decay to 6.25% of its original mass.

This can be obtained as follow:

Original amount (N₀) = 1 g

Amount remaining (N) = 0.0625 g

Decay constant (K) = 0.0462 / day

Time (t) =?

Log (N₀/N) = Kt/2.3

Log (1/0.0625) = 0.0462 × t / 2.3

Log 16 = 0.0462 × t / 2.3

1.2041 = 0.0462 × t /2.3

Cross multiply

0.0462 × t = 1.2041 × 2.3

Divide both side by 0.0462

t = (1.2041 × 2.3)/0.0462

t = 59.9 ≈ 60 days

Therefore, the time taken for the sample of the isotope to decay to 6.25% of its original mass is 60 days

5 0

3 years ago