Answer:
Explanation:
Given
radius of curve [tex]r=800\ m[/tex]
initial speed [tex]u=80\ kmph\approx 22.22\ m/s[/tex]
final speed [tex]v=60\ kmph\approx 16.67\ m/s[/tex]
time taken [tex]t=5\ s[/tex]
Tangential component of acceleration is given by
[tex]a_t=\frac{dv}{dt}[/tex]
[tex]a_t=\frac{16.67-22.22}{5}[/tex]
[tex]a_t=-1.1\ m/s^2[/tex]
Normal component
[tex]a_n=\frac{v^2}{r}[/tex]
[tex]a_n=\frac{22.22^2}{800}[/tex]
[tex]a_n=0.617\ m/s^2[/tex]
Net acceleration just after brakes is applied
[tex]a_{net}=\sqrt{(a_n)^2+(a_t)^2}[/tex]
[tex]a_{net}=\sqrt{(0.617)^2+(-1.1)^2}[/tex]
[tex]a_{net}=1.261\ m/s[/tex]
(b)acceleration after 5 s
Normal acceleration [tex]a_n=\frac{16.67^2}{800}[/tex]
[tex]a_n=0.347\ m/s^2[/tex]
Tangential acceleration [tex]a_t=-1.1\ m/s^2[/tex]
Net acceleration [tex]a_{net}=\sqrt{(a_n)^2+(a_t)^2}[/tex]
[tex]a_{net}=\sqrt{1.33}[/tex]
[tex]a_{net}=1.15\ m/s^2[/tex]
