In the context of conservation of energy, what does it mean if the net force $=$ $0$ on an object?

In which of the following reactions or decays is strangeness conserved? In each case, explain your reasoning.

(a) $K^{+}+{\mu }^{+}+{\nu }_{\mu }$

(b) $n+K^{+}\to p+{\pi }^0$

(c) $K^{+}+K^{-}\to {\pi }^0+{\pi }^0$

(d) $p+K^{-}\to {\Lambda }^0+{\pi }^0$

Which of the following statements is true according to the law of conservation of energy ($E$)?

Which equation represents the law of conservation of energy in a closed system?

Which of the following equations expresses the law of conservation of energy?

Which of the following scenarios best adheres to the law of conservation of energy ($E=\mathrm{constant}$)?

Which statement best describes the law of conservation of energy?

Mechanical energy is conserved in the presence of which of the following types of forces?

Which of the following is an example of energy conservation?