3. During a race, a sprinter increases from 5.0 m/s to 7.5 m/s over a period of 1.25s. What is the sprinter’s average accelerati
1 answer:
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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)
Explanation:
Given:
- mass of the child,
- height of the slide,
- initial velocity of the child at the slide,
- final velocity of the child at the bottom of slide,
(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:
Kinetic energy at the bottom of the slide:
(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:
Answer:
The third choice:
Explanation:
The cork is positively charged, therefore we know tat there must be excess of positively charged protons present.
The charge of a proton is
;
therefore, the number that makes up a charge of
is
which is the 3rd choice.