Answer:
7.35 J
Im assuming, upon answering the question, that the gravity in this scenario is 9.8? As 9.8 is the gravitational force upon the earth.
the International System of Units, the fundamental units are: The meter (symbol: m), used to measure length. The kilogram (symbol: kg), used to measure mass. The second (symbol: s), used to measure time. The ampere (symbol: A), used to measure electric current.
The answer is m/s hope it helps
F = m₁ a₁ = m₂ a₂
if m₁ = m and m₂ = 2m :
F = ma₁ = 2m a₂ ⇒ a₁ = 2 a₂
since v = at + v₀ with t = 3, v₀ = 0 ⇒ v = 3a:
v₁ = 2 v₂
since p = vm with v₁ = 2v and v₂ = v :
p₁ = v₁m₁ = 2v ⁻ m
p₂ = v₂m₂ = v ⁻ 2m
p₁ = p₂