A constant force of 14 N in the direction of a i j moves a

A constant force of 14 N in the direction of a = i + j moves a block on a frictionless surface from P_1(2, 3, 0) to P_2(4, 5, 0). Suppose distance is measured in meters. Find the work done.

Solution

Answer :

Given that a = i + j = < 1 , 1 > and P₁ = ( 2 , 3 , 0 ) and P₂ = ( 4 , 5 , 0 )

Then D = P₁P₂ = ( 4 - 2 , 5 - 3 , 0 - 0 ) = ( 2 , 2 , 0 )

The work done is W = a . D = < 1 , 1 > . < 2 , 2 , 0 > = 2 + 2 + 0 = 4 J