A car travels 120 meters in one direction in 20 seconds. Then the car returns ¾ of the way back in 10 seconds.
a) Calculate the average speed of the car for the first part of the trip.
b) Find the average velocity of the car.
a. d = 120 + (3/4)*120 = 120 + 90=210 m.
r = d/t = 210m/30s. = 7 m/s. = Avg.
speed.
b. V = (120-90)/30 = 1 m/s. = Average
velocity.
To solve this problem, we need to understand the concepts of average speed and average velocity.
a) Average speed is calculated by dividing the total distance traveled by the total time taken. In the first part of the trip, the car traveled a distance of 120 meters in 20 seconds. Therefore, the average speed can be calculated as follows:
Average speed (m/s) = Distance traveled (m) / Time taken (s)
Average speed = 120 m / 20 s = 6 m/s
Therefore, the average speed of the car for the first part of the trip is 6 m/s.
b) Average velocity takes into account both the magnitude (speed) and direction of motion. It is calculated by dividing the total displacement by the total time taken. Displacement refers to the change in position from the initial to the final position.
In this case, for the first part of the trip, the car travels 120 meters in one direction and then returns ¾ of the way back. This means the car's displacement for the first part of the trip is:
Displacement = (Total distance traveled in one direction) - (¾ of the total distance traveled in one direction)
Displacement = (120 m) - (¾ * 120 m)
= 120 m - 90 m
= 30 m (in the original direction)
Now, let's calculate the average velocity for the first part of the trip:
Average velocity (m/s) = Displacement (m) / Time taken (s)
Average velocity = 30 m / 20 s
= 1.5 m/s
Therefore, the average velocity of the car for the first part of the trip is 1.5 m/s in the original direction.