The speed of the raft if the speed of the patrol-boat was 12 km/hour, and it caught the raft in 5 hours 20 min later is 2.857 km/hours.
What is the speed of a body?
The speed of a body is the rate at which it covers the total distance is in the time taken. The speed of the body is given as,
Here, (d) is the distance travelled by the body, and (t) is time taken by the body to cover that distance.
A raft was sent away from point A downstream. A patrol-boat left A 5 hour and 20 min later and caught up with the raft 20 km away from point A.
Total time the patrol boat took in hours is,
T=5+0.3333
T=5.3333 hours
The speed of the patrol boat is 12 km/hour, and it caught up with the raft 20 km away from point A. Thus, the time taken with this speed to cover 20 km distance is,
T=1.6667 Hours
Thus, the total time is,
T=5.3333+1.6667
T=7 Hours
Now as the raft travel 20 km in 7 hours. Therefore, find the speed of raft by putting the values in above formula as,
S=2.857 kmph