Consider a ball thrown straight up in the air. At what position is its kinetic energy a maximum?
2 answers:
Answer:
Explanation:
When a body is thrown upward, the body has it maximum velocity with the velocity of the throw and this velocity keep decreasing due to deceleration that is cause by acceleration due to gravity until it gets to the maximum height where the velocity is zero.
Since kinetic energy is determine by.
K.E = ½mv²
The mass of the body is constant all through.
Then, the maximum velocity is at the point of thrown, then the body has it maximum kinetic energy at the point of throw.
If we considered when it is landing too
It will have a maximum velocity at the point of throw again, where it lands on the hand.
The same kinetic energy will be recorded at the point of thrown and at the point it landed on his hands back.
This is why it has been recorded that, a straight bullet fired upward can kill someone at the point of return, because it will land at the same velocity it left the ground
You might be interested in
Answer:
The ratio of the energy stored by spring #1 to that stored by spring #2 is 2:1
Explanation:
Let the weight that is hooked to two springs be w.
Spring#1:
Force constant= k
let x1 be the extension in spring#1
Therefore by balancing the forces, we get
Spring force= weight
⇒k·x1=w
⇒x1=w/k
Energy stored in a spring is given by where k is the force constant and x is the extension in spring.
Therefore Energy stored in spring#1 is,
⇒
⇒
Spring #2:
Force constant= 2k
let x2 be the extension in spring#2
Therefore by balancing the forces, we get
Spring force= weight
⇒2k·x2=w
⇒x2=w/2k
Therefore Energy stored in spring#2 is,
⇒
⇒
∴The ratio of the energy stored by spring #1 to that stored by spring #2 is 2:1