Average speed is same as the actual speed in case of a body having uniform motion​

Plss anybody know how to do this? ? i need the answers from a through d

Order the sequence of ideas that lead to marie curies discovery of radioactive elements number the events in chronological order starting with the oldest

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?