Answer:
-6112.26 J
Explanation:
The initial kinetic energy, 
is given by
} where m is the mass of a body and 
is the initial velocity
The final kinetic energy, 
is given by
where 
is the final velocity
Change in kinetic energy, 
is given by
Since the skater finally comes to rest, the final velocity is zero. Substituting 0 for and 12.6 m/s for and 77 Kg for m we obtain
From work energy theorem, work done by a force is equal to the change in kinetic energy hence for this case work done equals <u>-6112.26 J</u>
Answer:
True The net force must be zero for the acceleration to be zero
Explanation:
In order to analyze the statements of this problem we propose your solution.
First let's look at Newton's first, which stable that every object is at rest or with constant speed unless something takes it out of this state (acceleration)
Now let's look at the second postulate, which says that force is related to the product of the mass of a body and its acceleration.
As a result of these two laws, for a body is a constant velocity the summation force on it must be zero.
Now we can analyze the statements given.
True The net force must be zero for the acceleration to be zero
False. If the force is different from zero, there is acceleration that changes the speeds
False. There may be forces, but the sum of them must be zero
False. If a force acts, the acceleration is different from zero and the speed changes
Answer:
51793 bright-dark-bright fringe shifts are observed when the mirror M2 moves through 1.7cm
Explanation:
The number of maxima appearing when the mirror M moves through distance \Delta L is given as follows,
Here,
= is the distance moved by the mirror M
is the wavelenght of the light used.
= 0.017m
Therefore, 51793 bright-dark-bright fringe shifts are observed when the mirror M2 moves through 1.7
Explanation:
Christmas tree production occurs worldwide on Christmas tree farms, in artificial tree factories and from native strands of pine and fir trees. Christmas trees, pine and fir trees purposely grown for use as a Christmas tree, are grown on plantations in many western nations, including Australia, the United Kingdom and the United States. In Australia, the industry is relatively new, and nations such as the United States, Germany and Canada are among world leaders in annual production.
Great Britain consumes about 8 million trees annually, while in the United States between 35 and 40 million trees are sold during the Christmas season. Artificial Christmas trees are mostly produced in the Pearl River delta area of China. Christmas tree prices were described using a Hotelling-Faustmann model in 2001, the study showed that Christmas tree prices declined with age and demonstrated why more farmers do not price their trees by the foot. In 1993, economists made the first known demand elasticity estimates for the natural Christmas tree market.
