Answer:
(a)Work done and ΔE are negative
(b)Work done and ΔE are negative
(c)Work done and ΔE are positive
Explanation:
(a) When the two balls collide, the first billiard ball transfers its kinetic energy to the second ball which consequently starts rolling as the system ball comes to rest. Therefore, the decrease in internal energy takes places for both the system and energy transfer. Conclusively, Work done and ΔE are negative
(b) The drop of a book in this case system from a height transfers the potential energy to kinetic energy. Therefore, both the work is done by system on the floor and internal energy of the system decreases. In conclusion, Work done and ΔE are negative
(c) A father pushing daughter on swing which is system implies that he applied some force therefore transferring energy from the source to system. This means the internal energy of the system increases and so both the work done and ΔE are positive
A mechanical advantage less than ' 1 ' means the output <u>force</u> is less than the input
force. But <em>distance</em> is gained ... the load moves farther than the driving force moves.
An example of all this is a big father and his little 4-year-old daughter playing
on the see-saw in the park. He adjusts the board so that he's much closer
to the pivot than she is, and that way, their weights can balance each other.
It's set up so that the mechanical advantage from him to her is less than ' 1 '.
Now, look at what happens when Dad sits down on his end of the see-saw,
and pushes it down with his 180 pounds of force. At the other end, the board
is barely lifting her with a force of just 30 pounds. BUT ... as he sinks down
only 1 foot against his end of the board, <em>her</em> end rises 6 feet off the ground.
The temperature rises during boiling.
<h2>The K.E of the charge is 1.02 x 10⁻¹⁷ J</h2>
Explanation:
When the charge of 2e is placed in between the plates .
The force applied on this charge by plates is = q E
here q is the magnitude of charge = 2 e = 2 x 1.6 x 10⁻¹⁹ C
and E is the magnitude of electric field intensity
The work done = Force x displacement
Thus W = q E x S
here S is displacement
Therefore W = 2 x 1.6 x 10⁻¹⁹ x 4 x 8
= 1.02 x 10⁻¹⁷ J
This work will be converted into the kinetic energy of charge .
Thus K.E = 1.02 x 10⁻¹⁷ J
OPTION C is the correct answer.
