Answer:
D. in a closed system, an object's momentum before a collision will equal its momentum after the collision.
Explanation:
As we know by newton's II law we have

so we will have
F = net force on the system
= change in momentum
so we can say if the momentum is conserved or the initial momentum of the system will be equal to the final momentum of the system
then we will say that

so net force on the system must be ZERO
so in such type of questions the system must be isolated and there is no external force on it
so correct answer will be
D. in a closed system, an object's momentum before a collision will equal its momentum after the collision.
Answer:
0.3 eV, 0.5eV,, 8 eV, 2.0eV, 2.50 eV, 2.8 eV
Explanation:
In a given material the emission and absorption spectra are equivalent, for which the emission spectrum observed at high temperature for the material corresponds to the transition between the energy states of the material, the process is that the electrons exist from the ground state until an excited state and after a short period of time or these electrons relax emitting photons.
In the absorption process, the material is at low temperature, ideally at A = 0K, whereby all states are in the ground state and all excited states are empty. therefore it can absorb the beam energy for each transition given from the ground state to each excited edtado.
Consequently, the lines above the absorption oscillate lines coincide with the lines of emotion, this we see lines oscillate at 0.3 eV, 0.5eV,, 8 eV, 2.0eV, 2.50 eV, 2.8 eV
The second, fourth, and seventh answers apply. Energy in a closed system is conserved, but it can change form
On the surface of the earth, an object with a mass of 100 kg will weigh approximately 980 Newtons.
Please rate Brainliest (: