Answer:
A) Energy is dissipated into heat and sound energy due to Friction
B) The energy goes into heat and sound energy due to friction again, otherwise the cart would accelerate due to an unbalanced force. Therefore, we know there's friction, and the friction causes energy loss.
Answer:
According to Einstein's famous equation, matter can convert into energy (and viceversa) as follows:
where
E is the energy
m is the mass
c is the speed of light (
)
Given the huge value of 
, we see that even a tiny amount of matter is able to release a huge amount of energy, when the whole mass is converted into energy. This is precisely what happens in nuclear reactions. For example, in the process of nuclear fusion (that occurs in the core of the stars), two light nuclei fuse together into a heavier nucleus. The mass of the final nucleus is lower than the total mass of the initial nuclei, so part of the mass has been converted into energy according to the equation above: this is why the amount of energy produced by stars is so big.
If the ladder is vertical, then the work done in ascending equals his increase in potential energy.
For a man of mass (m) climbing height (h), the PE is (mgh), where g is the acceleration due to gravity.
If he does this in time t, his average power (rate of working) is:
mgh / t
= 80 * 9.81 * 6 / 12
= 392.4 W.
If the ladder is not vertical but inclined at an angle the horizontal, the power is mgh sin(a) / t.
Answer:
1.8m/s
Explanation:
We know that the momentum of an impact of a body is the mass times he velocity
M= mv
Given data
Mass m= 10kg
Momentum M= 18 kg.m/s
Velocity v=?
We can solve for velocity by submitting our given data in the momentum equation
18 = 10*v
v= 18/10
v= 1.8m/s
Use your units !
"Period" is time . . . 12 seconds.
"Frequency" how often . . . " ___ PER time". Time is in the denominator.
"12 seconds per wave" means
1 wave / 12 seconds
= ( 1 / 12 ) (wave/second)
= 0.08333... wave per second
= 1/12 Hz.
