Answer:
1) 2.5 m/s
2) The distance is 70 m
The displacement is 40 m
3) The average speed is 4.67 m/s
The average velocity is 2.67 m/s
4) The velocity time graph will give the acceleration of the motion
Explanation:
1) The instantaneous velocity is given by the slope at 12 seconds as follows;
Since the distance varies directly with the time from 11 to 15 seconds, the velocity is constant within that time period and is given by the relation;
Velocity = Displacement/(Time duration of displacement)
Velocity = (Final position - Initial position)/(Time duration for the change in position)
Velocity = (-10 - (-20))/(15 - 11) = (-10 + 20)/4 = 10/4 = 2.5 m/s
2) The distance moved by the object between 0 and 15 seconds is given as follows;
Distance = Position 30 to position -25 and from position -25 to position -10
Distance = 30 - (-25) + (-10 - (-25)) = 55 + 15 = 70 m
The displacement = The overall change in position of the object which is the difference between the first and last position;
Displacement = 30 - (-10) = 30 + 10 = 40 m
3) The average speed = Distance/Time = 70/15 = 14/3 = 4.67 m/s
The average velocity = Displacement/Time = 40/15 = 2.67 m/s
4) The velocity time graph will indicate the acceleration of the motion.
