Resistance of a material being scratched in known as

What happens to the potential energy of a book that is dropped from a desk to the floor?

Debora [2.8K]

Answer:

D. It is converted into kinetic energy.

Explanation:

When a book is dropped from a desk to the floor, the potential energy of the book is converted to kinetic energy as it falls.

Potential energy of a body is the energy due to the position of the body.
At a particular height, the potential energy is maximum.
A body with mass and moving with velocity will have kinetic energy
As the book drops through the height, to conserve energy, the potential energy is converted to kinetic energy.

4 0

3 years ago

PLS HELP: CHEMISTRY

user100 [1]

Answer:

3.59x10^21 molecules

Explanation:

1mole of a substance contains 6.02x10^23 molecules.

Therefore, 1mole of C8H18 will also contain 6.02x10^23 molecules

1mole of C8H18 = (12x8) +(18x1) = 96 + 18 = 114g.

1mole (i.e 114g) oh C8H18 contains 6.02x10^23 molecules.

Therefore, 0.68g of C8H18 will contain = (0.68 x 6.02x10^23)/114 = 3.59x10^21 molecules

7 0

3 years ago

Analysis of skunk spray yields a molecule with 44.77% c, 7.46% h and 47.76% s by mass. what is the empirical formula for this mo

stiv31 [10]

Suppose we have 100 gr of the substance. Then by weight, it would contain 44.77 gr of C, 7.46 gr of H and 47.76 gr of S. We need to look up the atomic weights of these atoms; M_H=1, M_C=12, M_S=32. The following formula holds (where n are the moles of the substance, M its molecular mass and m its mass): n=m/M. Substituting the known quantities for each element, we get that the substance has 3.73 moles of C, 7.46 moles of H and 1.49 moles of S. In the empirical formula for the molecule, all atoms appear an integer amout of times. Hence, for every mole of Sulfur, we have 2.5 moles of C and 5 moles of H (by taking the moles ratios). Thus, for every 2 moles of sulfur, we have 5 moles of C and 10 moles of H. Now that all the coefficients are integer, we have arrived at an empirical formula for the skunk spray agent: $C_5H_{10}S_2$

4 0

4 years ago

Does the identity of an atom change if we add or subtract electrons or neutrons? Explain.

AURORKA [14]

Adding or removing neutrons from the nucleus are how isotopes are created. Protons carry a positive electrical charge and they alone determine the charge of the nucleus. Adding or removing protons from the nucleus changes the charge of the nucleus and changes that atom's atomic number.

7 0

3 years ago

ubstance A undergoes a first order reaction A®B with a half-life, t½, of 20 min at 25 °C. If the initial concentration of A in a

Stells [14]

Answer : The concentration of A after 80 min is, 0.100 M

Explanation :

Half-life = 20 min

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$