Question

Can you please help me I’m confused with the negatives

Answer 1

Given that the mass of the ball, m = 5 kg

The initial velocity of the ball is

`V_o=6\text{ m/s}`

The final velocity of the ball is

`V_f=4\text{ m/s}`

We have to find the work done.

The work done can be calculated by the formula,

`\begin{gathered} W=\text{ change in kinetic energy} \\ =(1)/(2)m(V_f)^2-(1)/(2)m(V_o)^2 \end{gathered}`

Substituting the values, the work done will be

`\begin{gathered} W=(1)/(2)*5*(4)^2-(1)/(2)*5*(6)^2 \\ =40-90 \\ =-50\text{ J} \end{gathered}`

Thus, the work done will be -50 J