What is the energy in Joules of photons associated with light which has a frequency of 6.45x1014Hz?

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.

Aball has an initial velocity of 3 m/s. if there is no friction, what is the highest it could roll?

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?