Answer:
A)0.00022s b)40363.6N c) 0.025m/s
Explanation:
Mass = 24g = 0.024kg, distance though the target = thickness of the target = 25cm = 0.25m
Initial speed of the bullet = 1300m/s, final speed = 930m/s
Using equation of motion
Distance = 1/2(vf+vi)*t (time in seconds)
t = 0.25*2/(1300+930) = 0.00022s
B) force exerted on the body
F = ma = m* (vf-vi)/t = 0.024*(930-1300)/0.00022
F = -40363N, it is negative because the body decelerated during this motion
C) using law of conservation of momentum,
M1*U1+ M2*U2(M2and U1 are the mass and initial speed of the body) = M1V1+ M2V2
The target was at rest so initial speed U2 = 0
0.024*1300 + 360*0 = 0.024*930 + 360*V2
31.2 = 22.32+360*V2
31.2-22.33 = 360*V2
V2 = 8.88/360 = 0.025m/s
Gravity causes the motions of planets, stars, and galaxies. It's why the Moon orbits around the Earth, and the Earth orbits around the Sun, and the solar system orbits around the galaxy.
The first one is A and the second one would be C
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.
