Westonci.ca is the Q&A platform that connects you with experts who provide accurate and detailed answers. Discover comprehensive solutions to your questions from a wide network of experts on our user-friendly platform. Experience the ease of finding precise answers to your questions from a knowledgeable community of experts.
Sagot :
Given:
The initial height of the rock was,
[tex]h_i=5\text{ m}[/tex]The final height of the rock is,
[tex]h_f=1.5\text{ m}[/tex]The mass of the rock is,
[tex]m=0.5\text{ kg}[/tex]The travelling speed of the rock is,
[tex]v^{\prime}=8.0\text{ m/s}[/tex]To find:
a) The speed of the rock at Joe's head
b) how much work was done by air resistance
Explanation:
The displacement of the rock is,
[tex]\begin{gathered} h=h_i-h_f \\ =5-1.5 \\ =3.5\text{ m} \end{gathered}[/tex]The final speed at Joe's head is,
[tex]\begin{gathered} v=\sqrt{u^2+2gh} \\ =\sqrt{0^2+2\times9.8\times3.5} \\ =\sqrt{68.6} \\ =8.28\text{ m/s} \end{gathered}[/tex]Hence, the speed of the rock at Joe's head is 8.28 m/s.
b)
The speed at Joe's head was 8.0 m/s, and the loss of kinetic energy is,
[tex]\begin{gathered} \frac{1}{2}\times m[(8.23)^2-(8.0)^2] \\ =\frac{1}{2}\times0.5\times[3.73] \\ =0.93\text{ J} \end{gathered}[/tex]This loss of energy is the work done by the air resistance.
Hence, the work done by the air resistance is 0.93 J.
We hope you found what you were looking for. Feel free to revisit us for more answers and updated information. Thanks for using our platform. We aim to provide accurate and up-to-date answers to all your queries. Come back soon. Thank you for using Westonci.ca. Come back for more in-depth answers to all your queries.
