Question

A force of ( 3i^+4j^ ) displaces a particle through (i^+2√2 j^). Calculate the : (1). magnitude of force.(2). magnitude of displacement. (3). work done by the force.

Answer 1

$magnitude \: of \: force = \sqrt{ {3}^{2} + {4}^{2} } \\ = 5 \\ \\ mgnitude \: of \: displacement = \sqrt{ {1}^{2} + {(2 \sqrt{2} )}^{2} } = \sqrt{9} = 3 \\ \\ work \: done = f.s(dot \: product)$
F=(3i+4j)
s=(i+2√2j)

Work done–›(3i+4j).(i+2√2j)

–» (3+8√2)joules.