Describe when an object is said to be speeding up on a velocity versus time diagram.

A horizontal line on a speed-time graph represents a constant speed.

Explanation:

Acceleration is defined by a sloping line on a speed-time graph. The sloping line shows the object's speed is increasing. The target either accelerates or slows down.

Velocity-time graphs are being used to illustrate the acceleration for moving objects in a horizontal path. You can use them to display momentum and to sort out movement.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.