if a runner is moving with a speed of 1.5m/s and changes her speed to 2.1m/s over a time period of 3s, what is her average speed
To find the average speed, we need to consider the total distance covered by the runner and the total time taken.
Let's denote the initial speed as v1 = 1.5 m/s and the final speed as v2 = 2.1 m/s. The time period is given as t = 3 s.
To calculate the average speed, we need to find the total distance covered by the runner. Since we don't have additional information about the distance or the nature of the runner's motion, we cannot directly calculate the distance. However, assuming the acceleration is constant, we can use the equation of motion:
v2 = v1 + at
where "a" is the acceleration.
Rearranging the equation to solve for the acceleration, we have:
a = (v2 - v1) / t
= (2.1 m/s - 1.5 m/s) / 3 s
= 0.6 m/s / 3 s
= 0.2 m/s²
Now, using the equation of motion again, we can find the average speed:
average speed = (initial speed + final speed) / 2
average speed = (v1 + v2) / 2
= (1.5 m/s + 2.1 m/s) / 2
= 3.6 m/s / 2
= 1.8 m/s
Hence, the average speed of the runner over the time period of 3 seconds is 1.8 m/s.
All it asked for was the average speed
average speed = (v1 + v2) / 2
= (1.5 m/s + 2.1 m/s) / 2
= 3.6 m/s / 2
= 1.8 m/s
The rest is interesting but unnecessary.