A Maths Questions 10MARKS

1. Let u be the starting speed and v be the final speed

since average speed increases each hr by 5, in 5hours time, v = u+50
(v-u)/t=a(i) with constant acceleration

(u+50-u)/5=a
a=10km hr^-2
s=ut+1/2 at^2
300=5u+1/2*10*25
u=35km/hr

s=ut+1/2at^2
s=35*1.5+1/2*10*2.25
s=63.75km

(b)
10m/s=36km/hr (Nice, you are kidding me)
so in 5 hours time, v=u-360
(u-360+u)/5=a
a=-72km hr^-2

300=5u+1/2(-72)*25
u=240km/hr (What a speed)
s=240(.75)+1/2(-72)(.75)^2
=159.75km (Satisfy with it?)

2. 88
3. 2 (assume you are using 10進制 and this is a maths question)

2007-04-15 22:41:44 補充：
我好得閒回應d玩野o既題目架......
1+1+?=100
有冇人會寫88呀?
我想同你講byebye啫

1a.(300/5+5)*1.5=97.5km
1b.(300/5-10*60*60/1000)*45/60=18km
2.?=98
3.?=2

1.((300/5)+5)*1.5=97.5
Therefore the ans of a is 97.5km
((300/5)-10)*0.75=37.5
Thus the ans of b is 37.5km
2:98
3:2
I'm not sure about the ans is correct or not