Answer:
The position of the earth and moon.
Explanation:
The position of the earth and moon are the two main factors.
Hope this helps, have great day/night!
Net force is basically the force an object has when changing direction, so the answer would be D.
Answer:
They can generate potentials spontaneously because they have Unstable Membrane Potentials.
Explanation:
Autorythmic cells or Pacemaker cells are cells that provide Action potentials (electrical impulses) that starts off the cardiac cycle.
N:B This action potential is created spontaneously.
To explain further, the heart originate in specialized cardiac muscle cells, called autorhythmic cells, that can excite themselves and therefore are able to generate an action potential without external stimulation by nerve cells. And this sets the cardiac cycle i
(Pumping of the heart) into motion. (The pace maker potential)
The Autorhythmic cells create an action potential spontaneously
And this is possible because they have an UNSTABLE RESTING POTENTIAL that is continuously depolarizing, while it drifts slowly toward threshold. As Na+ ions enter the cell, the inner surface of the plasma membrane becomes less negative gradually, thus generating the pacemaker potential.
Answer: 
Explanation:
Given
Length of plank is 1.6 m
Force 
is applied on the left side of plank
Force 
is applied 43 cm from the left end O.
Mass of the plank is 
for equilibrium
Net torque must be zero. Taking torque about left side of the plank
Net vertical force must be zero on the plank
<span>The force would double.</span>
