Respuesta :
Answer:
(a) Potential energy of the child is converted into the kinetic energy at the bottom off the slide and a part of which is lost into friction generating heat between the contact surfaces.
(b) [tex]U=668.16\ J[/tex]
Explanation:
Given:
- mass of the child, [tex]m=24\ kg[/tex]
- height of the slide, [tex]h=3.3\ m[/tex]
- initial velocity of the child at the slide, [tex]v_i=0 m.s^{-1}[/tex]
- final velocity of the child at the bottom of slide, [tex]v_f=3\ m.s^{-1}[/tex]
(a)
∴The initial potential energy of the child is converted into the kinetic energy at the bottom off the slide and a part of which is lost into friction generating heat between the contact surfaces.
Initial potential energy:
[tex]PE=m.g.h[/tex]
[tex]PE=24\times 9.8\times 3.3[/tex]
[tex]PE=776.16\ J[/tex]
Kinetic energy at the bottom of the slide:
[tex]KE=\frac{1}{2} m.v^2[/tex]
[tex]KE= 0.5\times 24\times 3^2[/tex]
[tex]KE= 108\ J[/tex]
(b)
Now, the difference in the potential and kinetic energy is the total change in the thermal energy of the slide and the seat of her pants.
This can be given as:
[tex]U=PE-KE[/tex]
[tex]U=776.16-108[/tex]
[tex]U=668.16\ J[/tex]
