Question

List the following items in order of decreasing speed, from greatest to least: (i) A wind-up toy car that moves 0.15 m in 2.5 s. (ii) A soccer ball that rolls 2.3 m in 0.55 s. (iii) A bicycle that travels 0.60 m in 0.075 s. (iv) A cat that runs 8.0 m in 2.0 s. Knight, Randall D., (Professor Emeritus). College Physics (p. 28). Pearson Education. Kindle Edition.

Answer 1

(iii) > (ii) > (iv) > (i)

Step-by-step explanation:

Part (i):

`\textrm{Speed of the wind-up toy} = \frac{\textrm{distance traveled}}{\textrm{Time taken}}\\\Rightarrow v_1=(0.15\ m)/(2.5\ s)\\\Rightarrow v_1 = 0.06\ m/s`

Part (ii):

`\textrm{Speed of the soccer ball} = \frac{\textrm{distance traveled}}{\textrm{Time taken}}\\\Rightarrow v_2=(2.3\ m)/(0.55\ s)\\\Rightarrow v_2 = 4.18\ m/s`

Part (iii):

`\textrm{Speed of the bicycle} = \frac{\textrm{distance traveled}}{\textrm{Time taken}}\\\Rightarrow v_3=(0.66\ m)/(0.075\ s)\\\Rightarrow v_3 = 8.8\ m/s`

Part (iv):

`\textrm{Speed of the cat} = \frac{\textrm{distance traveled}}{\textrm{Time taken}}\\\Rightarrow v_4=(8.0\ m)/(2.0\ s)\\\Rightarrow v_4 = 4.0\ m/s`

From the above calculations, we have

`v_3>v_2>v_4>v_1`

So, the speed in the parts mentioned arranged in decreasing order as follow:

(iii) > (ii) > (iv) > (i)