In a 2 km race, B is defeated by A by 28m or 14 seconds. What is the time taken by A to complete the race.
Answers
Step-by-step explanation:
A’s time = t. Then we have:
A completes 1,000 m in time t
B completes 972 m in t
B completes 1,000 m in t + 7 s
So B completes the final 28 m in 7 s, so B’s speed is (28/7) m/s = 4 m/s.
A covers 1,000 m during the time B takes to cover 972 m so A’s speed must be (1,000/972) * 4 m/s.
A’s time over the course =
distance covered/speed
= 1,000 m/[(4,000/972) m/s]
= (972/4) s
= 243 s or 4 minutes and 3 seconds.
Answer:
A took 16 min 26 sec to complete the race. Please mark me as brainliest.
Step-by-step explanation:
Let A's speed be A and B's speed be B (All units in m, s, and m/s)
2000/B - 2000/A = 14 ...1 (Time = d/s)
(2000/A)B = 1972..2(In A's time with B's speed, B can cover 1972,i.e 2000- 28)
(2000A - 2000B)/AB = 14 (from 1)
2000A - 2000B = 14AB ..3
2000B/A = 1972 (from 2)
2000B = 1972A ...4
2000A - 1972A = 14AB (from 3 and 4)
28A = 14AB
B = 2
2000B = 1972A (from 4)
1972A = 4000
A = 4000/1972
T = D/S
Time taken by A = 2000/(4000/1972)
= 1972(2000/4000)
= 1972/2
= 986s = 16 min 26 sec