You can't get something from nothing is practically stating the law. The law means states that energy can't be created or destroyed, in other words, it's constant. So in saying so, you truly can't get something from nothing
Answer:
2. Using a shorter string of length L ′ ≈ 0.25 meters
5. Using a shorter string of length L ′ ≈ 0.5 meters
Explanation:
The period of a pendulum is given by

where
L is the length of the pendulum
g is the acceleration due to gravity
We see from the formula that the period of the pendulum depends only on its length, not on its mass or its amplitude of ocillation. Therefore, the only alterations that can change the period of the pendulum are the ones where its length is changed.
Moreover, we notice that the period is proportional to the square of the length: this means that in order to decrease the period of the pendulum (the problem asks us which alterations will reduce the period of the pendulum from 2 s to 1 s), the length of the pendulum should also be reduced.
Therefore, the only alterations that will reduce the period of the pendulum are:
2. Using a shorter string of length L ′ ≈ 0.25 meters
5. Using a shorter string of length L ′ ≈ 0.5 meters
Answer:
Explanation:
Speed of car =22.5miles/hr
U=22.5miles/hour
Applied brake and come to rest
Final velocity, =0
t, =2sec
Given that,
Speed=distance /time
Then,
Distance, =speed, ×time
Converting mile/hour to m/s
Given that
Use: 1 mile= 1600 m, 1 h= 3600s
22.5miles/hour × 1600m/mile × 1hour/3600s
Therefore, 22.5mile/hour=10m/s
Using speed =10m/s
Distance =speed ×time
Distance=10×2
Distance, =20m
The distance travelled before coming to rest is 20m.
A is the correct answer. It is an example of mutualism, where both species involved benefits.