A 30%-efficient car engine accelerates the 1500 car from rest to 12 m/s.
used effieciency equation
e= W out/Qh
used delta kinetic energy as work =(.5)m(v)^2, k=(.5)(1500)(12)^2 =86400
got an answer of 2900. its wrong though.
A typical photovoltaic cell delivers 4.2×10−3 W of electric energy when illuminated with 0.15 W of light energy.
used e= 4.2e-3/.15
answer=.03 but its wrong, is it suppost to be more complicated or something?