標題:
the average speed of the car
發問:
最佳解答:
Use the formula: distance = speed * time Let time1 be the time used to travel to the distinaiton. Let time2 be the time used to return to the original position. Distance to the distination = 60*time1 Distance for the return trip = 20* time2 60*time1 = 20*time2 (because distance to the distination = distance for the return trip) time2=3*time1 Total distance = distance to the distination + distance for the return trip =60*time1+20* time2 =120*time1 Total time = time1 + time2 =time1+3*time1 (because time2=3*time1 as shown above) =4*time1 Average apeed = total distance / total time =120*time1 / (4*time1) =30 The average speed of the car is 30 km/h
其他解答:
SET V=(2S)/(T+t) WHEN 60=S/T , 20=S/t THEN 60T=20t 3T=t AND THEN V=(2S)/(3t+t) =1/2(S/T)=1/2*60 =30 km/h|||||120/4=30km|||||let the distance be X km then the car go to the destination in X/60hour and it come back in X/20hour the average speed of car: 2X/(X/60+X/20) =2X/(4X/60) =2X*60/4X =30km/h|||||Suppose the length of the road is 60km the car need 1 hour to go and 3 hours to return so the car used 4 hours to travel 120km so the average speed is 120/4 = 30km/h|||||(60+20)/2 =40km/h
the average speed of the car
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A car travels at 60 km/h to a destination. On the return trip to the original position, due to traffic jam, the speed of the car is 20 km/h only. Find the average speed of the car最佳解答:
Use the formula: distance = speed * time Let time1 be the time used to travel to the distinaiton. Let time2 be the time used to return to the original position. Distance to the distination = 60*time1 Distance for the return trip = 20* time2 60*time1 = 20*time2 (because distance to the distination = distance for the return trip) time2=3*time1 Total distance = distance to the distination + distance for the return trip =60*time1+20* time2 =120*time1 Total time = time1 + time2 =time1+3*time1 (because time2=3*time1 as shown above) =4*time1 Average apeed = total distance / total time =120*time1 / (4*time1) =30 The average speed of the car is 30 km/h
其他解答:
SET V=(2S)/(T+t) WHEN 60=S/T , 20=S/t THEN 60T=20t 3T=t AND THEN V=(2S)/(3t+t) =1/2(S/T)=1/2*60 =30 km/h|||||120/4=30km|||||let the distance be X km then the car go to the destination in X/60hour and it come back in X/20hour the average speed of car: 2X/(X/60+X/20) =2X/(4X/60) =2X*60/4X =30km/h|||||Suppose the length of the road is 60km the car need 1 hour to go and 3 hours to return so the car used 4 hours to travel 120km so the average speed is 120/4 = 30km/h|||||(60+20)/2 =40km/h
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