A block constrained to move along a straight line is acted upon by a variable force

PHYSICS · Subjective · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

F(x)=k x^{2}

, directed along the positive

x

–axis. The block travels from

x=0

x=3.0\,\text{m}

and is found to have gained

54\,\text{J}

of work. (a) Find the numerical value of the constant

k

with proper units. (b) Using the value of

k

obtained in part (a), calculate the additional work done by the same force when the block is further displaced from

x=3.0\,\text{m}

x=5.0\,\text{m}

. (c) If the mass of the block is

1.5\,\text{kg}

and its speed at

x=0

2.0\,\text{m\,s}^{-1}

, determine its speed at

x=5.0\,\text{m}