A bacterium moves with a speed of 2.3 Âµm/s across a petri dish with radius r = 9.2 cm. How long does it take the bacterium to traverse the petri dish along its diameter?
Speed=2.3 Âµm/s =2.3×10ʌ-6m/s
Time =distance /speed
Time =0.092/2.3×10ʌ-6m/s=40000s =11.11 hours this is time taken by bacterium across a petri dish
Now time taken along the its diameter = 0.092×2/2.3×10ʌ-6m/s =80000s =22.22 hours
Sitting beside a friend on a park bench, you grab her hat and start running in a straight line away from her. Over the first 16.0 m, you accelerate at 1.5 m/s2 up to your maximum running speed. You then continue at your maximum running speed for 13.0 s more before your friend catches you. How far from the bench did you get before being caught? How long did it take for your friend to catch you?
Initial velocity =0m/s
Time running at max speed =13s
Final velocity = 2×16×1.5=6.92m/s2
Distance=initial distance + initial velocity× time +half× square time× acceleration
Time= (16/0.75)=4.6 s