Question

The velocity graphs pictured below represent the motions of five different colored objects of identical mass, with the color of the graph corresponding to the color of the object.
What is the order of objects, according to the magnitudes of the net forces they are experiencing during the time represented by their graphs, greatest first?

• A. Blue, purple, red, yellow, green
• B. Purple, red, yellow, blue and green tie
• C. Blue and green tie, yellow, purple, red
• D. Purple, red, blue, yellow, green
• E. Yellow, red, purple, blue and green tie

Answer 1

The correct option is E Yellow, red, purple, blue and green tie

The magnitude of force acing on object is given by

$\left|F\right|=\left|ma\right|$

$=m\left|\frac{dv}{dt}\right|$

$⟹\left|F\right|\propto \left|\frac{dv}{t}\right|$

Hence magnitude of force on object is proportional to the magnitude of slope(m) of the given v-t curve.

$m_{yellow}>m_{red}>m_{purple}>m_{green}=m_{blue}$

Therefore this is the order of the magnitude of force acting on objects.