Why would physics be compulsory​

What are similarities and differences of reflection, refraction, diffraction and absorption?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?

Which substance partical has negligible massand travels around outsidethe nucleus