Thecovered distance by the river water in 15 minutes is 0.75km. Now, the velocity of the river is \[v=\dfrac{d}{t}=\dfrac{0.75}{\dfrac{1}{4}}=3\]km/h Additional information: Instantaneous speed is defined as the speed of a body at any instant of time. Suppose a body is moving, it starts its motion from time, t=0. Generallyspeaking, it takes the average person roughly between 10 and 12 minutes to walk 1 km, which means that the average walking speed is between 3.11 and 3.73 miles per hour. Numerous factors, such as age, gender, fitness level, and terrain, will affect the final time. The average walking pace is between 16:05 and 19:18 minutes per Themotorboat goes 30 km downstream and comes back in a total of 4hrs and 30mins. The speed of the current is: A) 5 km/hr B) 10 km/hr C) 15 km/hr D) 25 meters/minute. Answer: The speed of the motorboat in still water or ‘b’ = 15 km/hr. Let the speed of the river flow or the current = ‘r’ km/hr. Distance= 20km Time = 15 minutes = 1/4 hr ∴ Speed of the train = Distance/Time = 20/(1/4) = 80 km/h After increasing its speed by 10 km/hr, New spe. A train covers a distance of 20 km in 15 minutes. If its speed is increased by 10 km/hr, the time taken by it to cover the same distance will be: 13 minutes 20 seconds; 12 minutes; Sowe will first of change distance from km/hour to meter/sec by multiplying it with 5/18 and also change 15 minutes to seconds by multiplying it with 60. \begin{aligned} Speed = 5* \frac{5}{18} = \frac A cyclist covers a distance of 750 meter in 2 minutes 30 seconds. What is the speed in km/hr of cyclist. 16 km/hr; 17 km/hr; 18 km/hr; Aman walking at the rate of 5 km/hr. crosses a bridge in 15 minutes. The length of the bridge (in metres) is : (1) 600 (2) 750 (3) 1000 (4) 1250. View Answer. A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km/hr, the time taken by it to cover the same dis- tance will be : (1) 10 minutes (2) 13 minutes 20 sec Cruisingspeed: 431 km/h (268 mph) Average speed: 249.5 km/h (155 mph) (duration: 7 minutes and 20 seconds) or: A train can reach 300 km/h (186 mph) in 2 minutes and 15 seconds, while the maximum operational speed of 431 km/h (268 mph) can be reached after 4 minutes. Weare given that two thirds of the 6 km was covered at 4 km / hr i.e. 4 km distance was covered at 4 km / hr. Time taken to cover 4 km = 4 km / 4 km / hr = 1 hr = 60 minutes. Time left = 84 – 60 = 24 minutes. Now, the man has to cover remaining 2 km in 24 minutes or 24 / 60 = 0.4 hours. Speed required for remaining 2 km = 2 km / 0.4 hr = 5 v8yo5o.