Question

3.1 types of energy an object has a mass of 100 g and a kinetic energy of 5 j. what is the speed of the object? ○ 100 m/s ○ 5 m/s ○ 10 m/s ○ 50 m/s

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 of the object and $v$ is its speed. We need to solve for $v$.

Step2: Convert mass to kilograms

The mass $m$ is given as 100 g. Since 1 kg = 1000 g, we convert 100 g to kg: $m=\frac{100}{1000}=0.1\space kg$.

Step3: Rearrange the kinetic energy formula to solve for $v$

Starting with $KE = \frac{1}{2}mv^2$, we can multiply both sides by 2: $2KE = mv^2$. Then divide both sides by $m$: $v^2=\frac{2KE}{m}$. Finally, take the square root of both sides: $v = \sqrt{\frac{2KE}{m}}$.

Step4: Substitute the known values

We know $KE = 5\space J$ and $m = 0.1\space kg$. Substituting these into the formula for $v$: $v=\sqrt{\frac{2\times5}{0.1}}$.

Step5: Calculate the value inside the square root

First, calculate the numerator: $2\times5 = 10$. Then divide by $0.1$: $\frac{10}{0.1}=100$.

Step6: Take the square root

Now, take the square root of 100: $v=\sqrt{100}=10\space m/s$.

Answer:

10 m/s (corresponding to the option "10 m/s")