Answer:
2324 J
Explanation:
The formula for work is:
where 
is the force applied, and 
is the distance moved, in this case 
and we need to find 
Since the crate is not moving up or down, we conclude that the <u>normal force must be equal to the weight </u>of the object:
where 
is the normal force and 
is the weight, which is: 
, where g is the gravitational acceleration 
and 
is the mass 
.
---------
Thus the normal force is:
Now, the force due to the friction is defined as:
where 
is the coefficient of friction, 
So, for the crate to move, the force applied must be equal to the frictional force:
And now that we know the force we can calculate the work:
substituting known values:
Here are the missing questions:
(a) How fast is the skier moving when she gets to the bottom of the hill?
(b) How much internal energy was generated in crossing the rough patch?
Part A
The initial kinetic energy of the skier is:
Part of this energy is then used to do work against the force of friction. Force of friction on the horizontal surface can be calculated using following formula:
The work is simply the force times the length:
So when the skier passes over the rough patch its energy is:
When the skier is going down the skill gravitational potential energy is transformed into the kinetic energy:
So the final energy of the skier is:
This energy is the kinetic energy of the skier:
Part B
We know that skier lost some of its kinetic energy when crossing over the rough patch. This energy is equal to the work done by the skier against the force of friction.
Answer:
metal B
temperature flow from high region to low . metal B has more temperature than others
Answer:
6.58×10⁻¹⁸ J
Explanation:
Applying
E = kq²/r.................. Equation 1
Where E = potential energy, q = charge on each electron, r = distance between the electron, k = coulomb's constant.
From the question,
Given: r = 3.5×10⁻¹¹ m,
Constant: q = 1.6×10⁻¹⁹ C, k = 8.99×10⁹ Nm²/C²
Substitute these values into equation 1
E = (1.6×10⁻¹⁹)²(8.99×10⁹)/(3.5×10⁻¹¹)
E = 6.58×10⁻¹⁸ J
Answer:
Final velocity, v = 0.28 m/s
Explanation:
Given that,
Mass of the model, 
Speed of the model, 
Mass of another model, 
Initial speed of another model, 
To find,
Final velocity
Solution,
Let V is the final velocity. As both being soft clay, they naturally stick together. It is a case of inelastic collision. Using the conservation of linear momentum to find it as :
V = 0.28 m/s
So, their final velocity is 0.28 m/s. Hence, this is the required solution.
