It would be: Activation Energy = 300 KJ
Hope this helps!
Answer: the minimal force that you need to apply to move the bureau is F = 198.45N
Explanation:
If you want to move an object, you need to apply a force that is bigger than the force of the statical friction.
The force of statical friction can be written as.
Ff = k*N
where k is the coefficient of static friction, in this case, k = 0.45, and N is the normal force between the object and the surface.
In this case, the normal force is the weight of the bedroom bureau, this is:
N = m*g = 45kg*9.8m/s^2 = 441N
Then the force is:
Fr = 0.45*441N = 198.45N
This means that the minimal force that you need to apply to move the bureau is F = 198.45N
and after this point, the force of friction will work wit the kinetic coefficient of friction, that usually is smaller than the statical one.
Answer:
The magnifying power of this telescope is (-60).
Explanation:
Given that,
The focal length of the objective lens of an astronomical telescope, 
The focal length of the eyepiece lens of an astronomical telescope, 
To find,
The magnifying power of this telescope.
Solution,
The ratio of focal length of the objective lens to the focal length of the eyepiece lens is called magnifying of the lens. It is given by :
m = -60
So, the magnifying power of this telescope is 60. Therefore, this is the required solution.
Okay, so the density of water is 1g/cm3. In order for the cube to float, it has to be less than 1, and it will sink if it is more than 1 g/cm3. Use a triple beam balance to weigh the cube, looking at the metric ruler on the balance. Then, if the cube's density is more than 1, then you know it will float. If the density is less than 1, you know it will sink.
hope this helps, and I didn't know how to use the word "metric ruler"
