Question

1.44J = 1/2 x 4.5 x v2this is to find out the speed in a kinetic energy equation

Answer 1

Recall that the kinetic energy is given by

`KE=(1)/(2)\cdot m\cdot v^2`

Where KE is the kinetic energy, m is the mass, and v is the speed.

For the given case, we have

KE = 1.44 J

m = 4.5 kg

Let us substitute these values into the above equation and solve for speed (v)

`\begin{gathered} KE=(1)/(2)\cdot m\cdot v^2 \\ 1.44=(1)/(2)\cdot4.5\cdot v^2 \\ 1.44=2.25\cdot v^2 \\ (1.44)/(2.25)=v^2 \\ 0.64=v^2 \end{gathered}`

Take square root on both sides of the equation

`\begin{gathered} \sqrt[]{0.64}=\sqrt[]{v^2} \\ 0.8=v \\ v=0.8\; \; (m)/(s) \end{gathered}`

Therefore, the speed is 0.8 m/s