what is the shortest possible time in which a bacterium could drift at a constant speed of 3.5mm/s across a petri dish with a diameter of 8.4cm
(8.4 cm)/(0.35 cm/s) = ___ seconds
I don't know why they call it the "shortest" time. It is the required time, if drifting at that speed across the dish along a diameter.
24s
To determine the shortest possible time for a bacterium to drift across a petri dish, we can use the formula:
Time = Distance / Speed
First, let's convert the petri dish diameter to millimeters, since the speed of the bacterium is given in mm/s.
Diameter in millimeters = 8.4cm * 10 (to convert cm to mm)
Diameter in millimeters = 84 mm
Next, we need to find the distance the bacterium needs to cover. The distance the bacterium needs to drift is equal to the circumference of the petri dish, which can be calculated using the formula:
Circumference = π * Diameter
Circumference = 3.14 * 84 mm
Now, we have all the necessary information to calculate the time taken:
Time = Distance / Speed
Time = (3.14 * 84 mm) / 3.5 mm/s
Simplifying the equation:
Time = (263.76 mm) / 3.5 mm/s
Time ≈ 75.36 s
Therefore, the shortest possible time for a bacterium to drift at a constant speed of 3.5 mm/s across a petri dish with a diameter of 8.4 cm is approximately 75.36 seconds.