An automobile engine slows down from 4000rpm to 1100 rpm in 2.9 s . Calculate its angular acceleration, assumed constant.

If the force on an object is in the negative direction, the work it does on the object must be [2 points a) negative. b) positive c) the work could be either positive or negative, depending on the direction the object moves

What color of light must blue light mix with to create white light? a. yellow b. white c. blue d. green

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?