They use Newton to measure force
Answer:
Before: 0 m/s
After: -4 m/s
Explanation:
Before: Since you and your beau started at rest, your beau initial velocity is 0 m/s.
After: Since we have to conserve momentum,
momentum before push = momentum after push.
The momentum before push = 0 (since you and your beau are at rest)
momentum after push = m₁v₁ + m₂v₂ were m₁ = your mass = 60 kg, v₁ = your velocity after push = 3 m/s, m₂ = beau's mass = 45 kg and v₂ = beau's velocity.
So, m₁v₁ + m₂v₂ = 0
m₁v₁ = -m₂v₂
v₂ = -m₁v₁/m₂ = -60 kg × 3 m/s ÷ 45 kg = -4 m/s
So beau moves with a velocity of 4 m/s in the opposite direction
I believe it's B. the transmission of heat across matter
There may be an esoteric technical shade or nuance of difference. But I've been an electrical engineer for 40 years now, and have always used them interchangeably.
(I would have answered your question by saying "No.", but this website won't accept an answer that's less than 200 characters long.)