Question

1. observe: turn off show labels. next to

elease barrel,\ click play (▶). observe how fast the barrel moves as it floats down the river.
what happens when the barrel goes over the waterfall?

1. calculate: the two red flags are 100 meters apart. the time at which the barrel passes the flag is shown. remember, there are 60 seconds in a minute.

a. how many seconds did it take for the barrel to go 100 meters?

b. to find the barrel’s speed, use a calculator to divide the distance traveled (100 m) by the time it took the barrel to float 100 m. the units are meters per second (m/s).
what is the speed of the barrel?

(activity a continued on next page)

Explanation:

Step1: Understand the formula for speed

Speed is calculated by the formula \( \text{Speed} = \frac{\text{Distance}}{\text{Time}} \). Here, the distance traveled by the barrel is 100 meters. We need to find the time it took to travel this distance first (from part A, let's assume we found the time \( t \) seconds to travel 100 meters).

Step2: Apply the speed formula

Using the formula \( \text{Speed} = \frac{\text{Distance}}{\text{Time}} \), substitute Distance = 100 m and Time = \( t \) (from part A). For example, if from part A we found that the time \( t = 60 \) seconds (assuming a sample time, but in reality, we get \( t \) from the activity's observation), then \( \text{Speed} = \frac{100}{t} \) m/s. Let's say \( t = 60 \) seconds (as a sample, but the actual time would come from the activity), then \( \text{Speed}=\frac{100}{60}\approx1.67 \) m/s. But in general, we use the time obtained from part A (how many seconds it took to go 100 meters) and divide 100 by that time.

Answer:

To find the speed, use \( \text{Speed} = \frac{\text{Distance}}{\text{Time}} \). First, determine the time \( t \) (in seconds) the barrel took to travel 100 meters (from part A). Then, speed \( = \frac{100}{t} \) m/s. (The actual numerical answer depends on the time \( t \) obtained from the activity's observation, e.g., if \( t = 60 \) s, speed \( \approx 1.67 \) m/s)