<span>82.0 kg
I am going to assume that there is a typo for the number of joules of energy. Doing a google search for this exact question showed this question multiple times with a value of 4942 joules which makes sense given how close the "o" key is to the "9" key. Because of this, I will assume that the correct value for the number of joules is 4942. With that in mind, here's the solution.
The gravitational potential energy is expressed as the mass multiplied by the height, multiplied by the local gravitational acceleration. So:
E = MHA
Solving for M, the substituting the known values and calculating gives:
E = MHA
E/(HA) = M
4942/(6.15*9.8) = M
4942/60.27 = M
81.99767712 = M
Rounding to 3 significant figures gives 82.0 kg</span>
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[D. 2 protons, 2 electrons, and 1 neutron.]
As we know that, protons are embedded in the nucleus with neutron having no charge. So, nucleus has positive charge. Electrons are revolved around the nucleus of the atom. Proton has positive charge and electron has negative charge.
Number of proton = Number of electron.
Hence, both 2 protons and 2 electrons make the atom electrically neutral. So, the net charge of atom is 0. Neutron are the subatomic particle which has only mass.
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Answer:
2.5 cm
40 D
Explanation:
When the radius of curvature of a lens is divided by 2 we get the focal length of the lens.
Focal length is given by

The focal length of the lens is 2.5 cm
When we divide 1 by the focal length in the unit of meters we get the power of a lens
Power of a lens is given by

The power of the lens is 40 D
The weight should be shared between the two string equally. Therefore, tension in each string, T is;
T = 120 N/2 = 60 N