a) 
, 
The work done by the student in each trial is equal to the gravitational potential energy gained by the student:
where
m = 68 kg is the mass of the student
g = 9.8 m/s^2 is the acceleration of gravity
is the gain in height of the student
For the first student, 
, so the work done is
The second student runs up to the same height (3.5 m), so the work done by the second student is the same:
2) 
, 
The power exerted by each student is given by
where
W is the work done
t is the time taken
For the first student, and 
, so the power exerted is
For the second student, 
and 
, so the power exerted is
Answer:
The answer is "Option C".
Explanation:
It's evident from the figure below that after thirty minutes, not no more hydrogen can be created because all of the reactants have converted into products.
hydrogen gas created in cm cubes per period x = 20 seconds, y = 45 centimeters squared, and so on.
A reaction's terminus (the graph's flat line) indicates that no further products are being created during the reaction.
This is a ball and socket joint.
(a) 0.74 m/s^2
Explanation:
There are two forces acting on the skier: the component of the weight parallel to the slope, which acts downward, and the frictional force, which acts upward along the incline.
The component of the weight parallel to the inclined plane is:
where m is the mass of the skier, 
and 
.
The frictional force is instead
is the coefficient of friction for waxed wood on wet snow.
If we apply Newton's second law, we can write that the net force must be equal to the product of mass per acceleration:
And symplifying m, we can find the acceleration:
(b) 
Explanation:
This time, the skier is moving at constant velocity. Therefore, the acceleration is zero (a=0) and Newton's second law becomes:
By simplifying, we get
From which we can find the angle at which the skier could coast at a constant velocity:
The first law of thermodynamics states that energy can neither be created nor destroyed, but it can be converted from one form to another form.
The electric stove is supplying heat to the kettle, this makes the water particles in the kettle to gain more kinetic energy and to increase their motion until they gather enough energy to turn to vapor. The energy gained by the water particles is used to carry out the work of whistling of the kettle.
