In: Physics
Given that xo = 7m
and x = -3m
x-xo = -10m
apply v^2 = u^2+(2*a*(x-xo))
20^2 = u^2 -(2*a*10)
u^2 = 400+20a..........(1)
v = u+(a*t)
-20 = u+(a*4.2)....(2)
apply x - xo = (u*t)+(0.5*a*t^2)
-10 = (u*4.2)+(0.5*a*4.2*4.2)
-10 = 4.2*u + (8.82*a)......(3)
soliving (2) and (3) we get
-72 = 8.82*a
a = -72/8.82 = -8.2 m/s^2
initial velocity u = 14.3 m/s
avg velocity = 10/4.2 = 2.4 m/s