When the ball has left your hand and is flying on its own, its kinetic energy is
KE = (1/2) (mass) (speed²)
KE = (1/2) (0.145 kg) (25 m/s)²
KE = (0.0725 kg) (625 m²/s²)
<em>KE = 45.3 Joules</em>
If the baseball doesn't have rocket engines on it, or a hamster inside running on a treadmill that turns a propeller on the outside, then there's only one other place where that kinetic energy could come from: It MUST have come from the hand that threw the ball. The hand would have needed to do <em>45.3 J</em> of work on the ball before releasing it.
By definition, the kinetic energy is given by:
K = (1/2) * m * v ^ 2
where
m = mass
v = speed
We must then find the speed of both objects:
blue puck
v = root ((0) ^ 2 + (- 3) ^ 2) = 3
gold puck
v = root ((12) ^ 2 + (- 5) ^ 2) = 13
Then, the kinetic energy of the system will be:
K = (1/2) * m1 * v1 ^ 2 + (1/2) * m2 * v2 ^ 2
K = (1/2) * (4) * (3 ^ 2) + (1/2) * (6) * (13 ^ 2)
K = <span>
525</span> J
answer
The kinetic energy of the system is<span>
<span>525 </span></span>J
Answer:
the thickness required of a masonry wall L = 375mm
Explanation:
The detailed steps and appropriate use of fourier's law of heat conduction is as shown in the attached file.
For water, as the temperature goes up the density of the liquid water decreases therefore it becomes less dense so it tends to rise upward. And since the temperature here is higher, heat flows from the higher temperature to the lower so it releases energy to the environment. Therefore, the correct statements are 2, 3 and 5.
