The speed of two bodies are in ratio 2 : 3. If the difference in the time taken to cover 50 m is 20 sec., then Find the difference in their speeds.
Answer & explanation
Correct answer: option 2
S1 : S2
Speed 2 : 3 (given)
We know S ∝ \(\frac{1}{t}\)
S ⇒ 2 : 3
T ⇒ 3 : 2 ⇒ 1R= 20sec (given)
↓ ↓
×20 ×20
↓ ↓
60 s 40 s
Speed (S) = \(\frac{Distance (D)}{Time (T)}\)
S1 = \(\frac{50}{60}\) = \(\frac{5}{6}\) m/sec
S2 = \(\frac{50}{40}\) = \(\frac{5}{4}\) m/sec
Difference in their speeds are = \(\frac{5}{4}\) - \(\frac{5}{6}\)
= \(\frac{30 - 20}{24}\) = \(\frac{10}{24}\)
= \(\frac{5}{12}\) m/sec