呢條question係英文,希望好心人幫我解答下啦。
1.Joey ran in a park at a speed of 180 m/min for 1/2 hour.She then walked in the park at a speed of 120 m/min for 1/4 hour.
(a) Find the total distance she travelled.
(b) Find her average speed.
我要趕著做功課,help me! thx^-^
有rate的數學題唔識做...
2006-11-29 2:24 am
回答 (2)
2006-11-29 2:29 am
✔ 最佳答案
a)1/2h = 30min1/4h = 15min
total distance travelled=180x30+120x15=7200m=7.2km
b)speed=distance/time
=7200/(30+15)
=160m/min
2006-11-29 2:33 am
1(a) Total distance
= distance ran + distance walked
=180m/min * 1/2hour + 120m/min * 1/4hour
=180m/min * 1/2 * 60min + 120m/min * 1/4hour* 60min
=180m/min * 30min + 120m/min * 15min
=180*30m + 120*15m
=7200m
1(b) Average speed
= total distance travelled / total time elapsed
= 7200m / (1/2hour + 1/4hour)
=7200m / (30min+15min)
=160m/min
= distance ran + distance walked
=180m/min * 1/2hour + 120m/min * 1/4hour
=180m/min * 1/2 * 60min + 120m/min * 1/4hour* 60min
=180m/min * 30min + 120m/min * 15min
=180*30m + 120*15m
=7200m
1(b) Average speed
= total distance travelled / total time elapsed
= 7200m / (1/2hour + 1/4hour)
=7200m / (30min+15min)
=160m/min
收錄日期: 2021-04-12 22:57:34
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