Question

if a vehicle travels with a constant acceleration of 3km/hr for 5 hours, what was its intial velocity if the final velocity was 100km/hr

Answer 1

v = at + v₀ , where v₀ is the initial velocity

so after 5 hours ...

100 = 5(3) = v₀
v₀ = 85

(your acceleration should be 3 km/h^2)