Question

the kinetic energy of an object with a mass of 6.8 kg and a velocity of 5.0 m/s is \boxed{} j. (report the answer to two significant figures.)

Explanation:

Step1: Recall the kinetic energy formula

The formula for kinetic energy (\(KE\)) is \(KE = \frac{1}{2}mv^2\), where \(m\) is the mass and \(v\) is the velocity.

Step2: Substitute the given values

Given \(m = 6.8\space kg\) and \(v = 5.0\space m/s\). Substitute these into the formula:
\(KE=\frac{1}{2}\times6.8\times(5.0)^2\)
First, calculate \((5.0)^2 = 25\). Then, \(\frac{1}{2}\times6.8 = 3.4\). Now multiply \(3.4\times25\):
\(3.4\times25 = 85\) (since \(3\times25 = 75\) and \(0.4\times25 = 10\), \(75 + 10 = 85\)).

Step3: Check significant figures

The given values \(6.8\) (two significant figures) and \(5.0\) (two significant figures) result in the answer having two significant figures, which is already satisfied by 85.

Answer:

85