Kecepatan cahaya disimbolkan c . Kecepatan benda saat massanya bertambah 25% sebesar

TRK
• massa

m' = mₒ + 25% mₒ = 5/4 mₒ
v = __?

m' = mₒ / √(1 - (v/c)²)
5/4 mₒ = mₒ / √(1 - (v/c)²)
5/4 = 1 / √(1 - (v/c)²)
⅘ = √(1 - (v/c)²)
16/25 = 1 - (v/c)²
(v/c)² = 9/25
v/c = ⅗
v = ⅗ c ✔️