If 56.5kJ are needed to raise the temp by 90°C and if the heater is 60% efficient that means that:
60% X y = 56.5kJ
where y is the electrical energy in kJ that the heater will use.
y = 94.2kJ
Answer:
both magnesium and strontium have 2 valence electrons
Explanation:
potassium has 8 valence electrons, and nitrogen has 5.
The net force acting on the refrigerator is 400 N to the right.
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FURTHER EXPLANATION</h3>
The net force or resultant force is the sum of all the forces acting on a body or an object in x and y axes.
- Forces along the y-axis The forces that usually act on an object vertically (in the y-axis) are: gravitational force which is a downward force and the normal force which is an upward (perpendicular) force exerted by a surface on an object resting above it that keeps the object from falling.
- Forces along the x-axis These include the force or forces applied to cause a left or right motion of an object along the horizontal plane (called the Applied Force) and the force that opposes the motion or friction.
In this problem the forces acting on the x and y - axes can be determined:
Along the x-axis:
- gravitational force = -1960 N
- normal force = +1960 N
- Net force = -1960 N + 1960 N = 0
The gravitational force is the weight of the object obtained by multiplying the mass of the object (in kg) with the acceleration due to gravity, 9.8 m/s^2. It is given a negative (-) sign to indicate that it is a downward force.
Since the object is not falling through the surface, it can be assumed that the gravitational force and normal force are balanced. Hence, the size of the normal force is the same as the gravitational force but with the opposite direction indicated by the + sign for an upward force.
The forces along the x-axis are balanced (i.e. net force is zero) so the object neither moves upward or downward.
Along the y-axis
- applied force = +400 N
- friction = 0
- Net force = +400 N + 0 = +400 N
The applied force is +400 N. It is given a + sign to indicate that its direction is to the right.
The friction, as mentioned in the problem, is set to zero or "turned off".
The net force along the y-axis is +400. The forces are unbalanced so the object will move to the right as force is applied to it.
<h3>LEARN MORE</h3>
Keywords: net force, resultant force
There are so many to choose from, I'll give you two. One is a big one. The other so/so. People used to believe the earth was flat and you would fall off, until Christopher Columbus sailed across. And another interesting one is the vulcan planet theory, which is that there was an extra planet between Mercury and T sun. however it turned out to be false. So there, need anymore just tell me.
