It takes 12.56 seconds. Find the radius of the circular trajectory. Circular track radius: = perimeter/2pi = (15 *12.56)/2pi =188.4/2pi = 29.98 (m) ... The circular track radius is 29.98 square meters, and Mr. Huang is driving at a speed of 50km/h ..
He slowed down to 40 kilometers per hour; We will arrive at our destination in half an hour? Seek the average driving speed of Mr. Huang throughout the journey. Average driving speed of Mr. Huang: = total distance/total time = (50 * 0.5+40 * 0.5)/(0.5+0.5) = (25+20)/1= 45 (km/h) ... The average driving speed of Mr. Huang is 45 kilometers.
After 50 kilometers.
He slowed down to 40 kilometers per hour.
Drive another 50 kilometers. What is the average speed of Mr. Qiu Hong's speedboat during the whole journey? The average speed of Mr. Hong's speedboat during the whole journey: = total distance/total time = (50+50)/(50/60+50/40) =100/(5/6+1.25) = 48 (km/h). ...
Walk to the second place at an average speed of 1.2 meters per second; Zhuo feng starts with B.
Ride to a place at an average speed of 4.8 meters per second? They set off at the same time
Go the same way; They met on the road five minutes later. How long is this road? ***5min=5*60s=300s This path is long: =1.2 * 300+4.8 * 300 = 6 * 300 = 1800 (m) ... This path is long1800m.
1. 15 times 12.56 equals 188.4. 188.4 divided by 3. 14 equals 60. Divide by 2.
Equal to 30. Description: 15 system speed.
And 12.56 is the time.
So speed times time equals circumference.
The circumference divided by (3. 14) equals the diameter.
Diameter divided by 2
Equal to the radius. 2.50 times 0.5 equals 25. 40 times 0.5 equals 80. The last 25 plus 80 equals 125. Then 125 divided by 1 equals 125km/h/h Explanation: 50 series speed.
(Half an hour) 0.5 is time.
So speed times time equals distance, and 40 times 0.5 equals 80 is the same.
The last two distances are buried.
Distance divided by time equals speed. 3.50 divided by 60 equals 5/6. 50 divided by 40 equals 1 and 1. Buried twice: 5/6 plus 1 and 1 equals 2 and 12.
Equivalent to 48 kilometers per hour. 1.2 times 5 minutes, that is, (300 seconds) equals 360. 4.8 times 5 minutes (that is, distance), that is, (300 seconds) equals 1440. Finally, 360 plus 1440 equals 1800.
So you can know the exam. Come on! !
Reference: self