Answer:
3.95979 m/s
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
[tex]v^2-u^2=2as\\\Rightarrow as=\frac{v^2-u^2}{2}\\\Rightarrow as=\frac{0^2-2.8^2}{2}\\\Rightarrow as=-3.92[/tex]
Here [tex]s=\frac{1}{2}s[/tex]
[tex]\\\Rightarrow as=-7.84\ m/s^2[/tex]
[tex]v^2-u^2=2as\\\Rightarrow -u^2=2as-v^2\\\Rightarrow u=\sqrt{v^2-2as}\\\Rightarrow u=\sqrt{0^2-2\times -7.84}\\\Rightarrow u=3.95979\ m/s[/tex]
Initial velocity of the puck should be 3.95979 m/s