Question

SHOW ALL WORKThe height of the second hill is 50 meters. When the 300kg car reaches the top of the second hill:a. What is the potential energy of the car?b. What is the kinetic energy of the car?

Answer 1

a. 147000 J

b. 88200 J

Explanation:

Given:

height of the first hill (h1) = 80 m

height of the second hill (h2) = 50 m

mass (m) = 300

We can calculate the speed on the second hill using the following formula:

`\begin{gathered} v_2=√(2g\cdot\left(h_1-h_2\right)) \\ \text{ We replacing} \\ v_2=√(2\cdot9.8\left(80-50\right)) \\ v_2=24.25\text{ m/s} \end{gathered}`

a.

We can calculate potential energy using the following formula:

`\begin{gathered} E_P=m\cdot g\cdot h \\ \text{ We replacing} \\ E_P=300\cdot9.8\cdot50 \\ E_P=147000\text{ J} \end{gathered}`

b.

We can calculate the kinetic energy using the following formula:

`\begin{gathered} E_K=(1)/(2)mv^2 \\ \text{ We replacing} \\ E_K=(1)/(2)\cdot300\cdot24.25^2 \\ E_K=88209.375\cong88200\text{ J} \end{gathered}`