The frictional force acts upwards, so as to oppose the downward force of gravity. The reason that pressing against the wall harder makes the book stick more is because the reaction force from the wall increases and frictional force is directly proportional to reaction force.
Answer:
<em>a. 137.5 m</em>
<em>b. 550 m</em>
Explanation:
<u>Accelerated Motion
</u>
If an object is changing its velocity at a constant rate, it has a uniformly accelerated motion. When the object is moving in one fixed axis, then the sign of the acceleration is negative if the object is braking, and positive if the object is increasing its speed.
The initial speed vo, final speed vt, acceleration a, and distance traveled x are related by the formula
a. The Race Car A has an initial speed of 55 m/s and it's said to stop. We must find at what distance it goes to vf=0. This means that the above formula becomes
Solving for x
The acceleration is , negative because it's against the movement. Thus
b. If the car is going twice as fast (v0=110 m/s), then
The minimum size copper equipment grounding conductor that is required is ; #4 copper
<h3>Equipment grounding conductor </h3>
An Equipment grounding conductor is a conductive part of ground fault current path which connects the non-conducting metallic parts of the euipment together and also connects the system grounded conductor.
For a copper euipment grounding conductor required to serve a control center connected to a 300 amp over current device the minimum size of copper is #4 copper
Hence we can conclude that The minimum size copper equipment grounding conductor that is required is ; #4 copper.
Learn more about Equipment grounding conductor : brainly.com/question/14124204
Answer: The plasma membrane is called a selectively permeable membrane as it permits the movement of only certain molecules in and out of the cells. Not all molecules are free to diffuse. If plasma membrane ruptures or breaks down then molecules of some substances will freely move in and out of the cells. Semipermeable membrane describes a membrane that allows some particles to pass through (by size), whereas the selectively permeable membrane "chooses" what passes through (size is not a factor). Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.
Explanation: hope this helps you with your work/assingment! Have a wonderful day/night!
The forces that drive Plate Tectonics include: Convection in the Mantle (heat driven) Ridge push (gravitational force at the spreading ridges) Slab pull (gravitational force in subduction zones)