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
There are a lot of things about this whole statement that bother me,
but I'm pretty sure you're not interested in those. You just want a word
to glue onto the end and complete the statement. OK. Use "inertia".
Since it moves 5 m/s faster every second, after 20 seconds it's moving 100 m/s faster than when it started speeding up.
If it was moving at 14 m/s when the acceleration began, it's moving at 114 m/s at the end of the 20 seconds. Its velocity is <em>114 m/s North.</em>
That's 255 mph !
An example you could use for this would be if you threw a pencil across the room 10m away. the pencil would have travelled 10m(N). you could determine the objects speed by using the formula speed=distance/time. you would have had to time how long it took for the pencil to hit the 10m marking and divide 10 by however many seconds it took.
D.N(Newton) this is the S.I unit for force
