Johnny has thrown a 2kg ball. The ball has an acceleration of 20m/s2. How much was the force that Johnny used?

Write the overall equation for the reaction for lithium battery

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?

What is the most common reason for matter changing its state?