Answer:
Significant digits (also called significant figures or “sig figs” for short) indicate the precision of a measurement. A number with more significant digits is more precise. For example, 8.00 cm is more precise than 8.0 cm.
Answer:
I would believe that it would be the last option
Explanation:
Physical science is a type of science that mainly focuses on natural objects that are not alive, such as minerals and rocks.
1) Frequency: 
the energy of the photon absorbed must be equal to the ionization enegy of the atom, which is
The energy of a photon is given by
where 
is the Planck's constant. By using the energy written above and by re-arranging thsi formula, we can calculate the frequency of the photon:
2) Wavelength: 91.2 nm
The wavelength of the photon can be found from its frequency, by using the following relationship:
where 
is the speed of light and f is the frequency. Substituting the frequency, we find
Answer:
W = 3/2 n (T₁- T₂)
Explanation:
Let's use the first law of thermodynamics
ΔE = Q + W
in this case the cylinder is insulated, so there is no heat transfer
ΔE = W
internal energy can be related to the change in temperature
ΔE = 3/2 n K ΔT
we substitute
3/2 n (T₂-T₁) = W
as the work is on the gas it is negative
W = 3/2 n (T₁- T₂)
v2 = ?
m1 = 10kg
m2 = 70kg
v1 = 4m/s
E1 = E2
E1 = 1/2 * m1 * v1^2 = 1/2 * 10kg * 4m/s^2 = 80J
E2 = 1/2 * m2 * v2^2 = 80 J
v2 = √(E2/(2 * m2)) = √(80J/(2 * 70kg)) = about 0.76m/s
