- Messages
- 39
- Reaction score
- 24
- Points
- 18
Could you help me with 5(ii) plz?
Using s = ut + (1/2)a(t^2)
sP = 12t - 5(t^2)
sQ = 7t - 5(t^2)
3 sP = 8 sQ
3{12t - 5(t^2)} = 8 {7t - 5(t^2)}
36t - 15t^2 = 56t - 40t^2
5t( 5t - 4) = 0
so t = 4/5 = 0.8 s
V=u+at
vP = 12 +(-10*0.8) = 4 m/s
vQ = 7 + (-10*0.8) = -1 m/s (travelling in the opposite direction)