As per Definition of acceleration we know that rate of change in velocity of object is known as acceleration

so when we apply push on an object that push or applied force will change the velocity of object always
so correct answer must be
a.) changed the velocity
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.
During the first phase of acceleration we have:
v o = 4 m/s; t = 8 s; v = 13 m/s, a = ?
v = v o + a * t
13 m/s = 4 m / s + a * 8 s
a * 8 s = 9 m/s
a = 9 m/s : 8 s
a = 1.125 m/s²
The final speed:
v = ?; v o = 13 m/s; a = 1.125 m/s² ; t = 16 s
v = v o + a * t
v = 13 m/s + 1.125 m/s² * 16 s
v = 13 m/s + 18 m/s = 31 m/s
Answer:
Crumple zones are designed to absorb and redistribute the force of a collision. ... Also known as a crush zone, crumple zones are areas of a vehicle that are designed to deform and crumple in a collision. This absorbs some of the energy of the impact, preventing it from being transmitted to the occupants.