Answer:
Change in velocity and direction over a specific period of time.
Explanation:
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate the acceleration of an object.
Mathematically, acceleration is given by the equation;


Where,
a is acceleration measured in 
v and u is final and initial velocity respectively, measured in 
t is time measured in seconds.
Hence, the types of changes in motion that cause acceleration is a change in velocity and direction over a specific period of time.
Answer:

Explanation:
As we know that


also we know that

it is given as


also we can find the magnitude of two vectors as


similarly we have


now we know the formula of dot product as




Answer:
Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves.
Explanation:
The movement of the medium is different. In the longitudinal wave, the medium moves left to right, while in thee transverse wave, the medium moves vertically up and down. Longitudinal waves have a compression and rarefaction, while the transverse wave has a crest and a trough. Longitudinal waves have a pressure variation, transverse waves don't have pressure variation. Longitudinal waves can be propagated in solids, liquids and gases, transverse waves can only be propagated in solids and on the surfaces of liquids. Longitudinal waves have a change in density throughout the medium, transverse waves don't.
Answer:
(D) a brief early period of hyper rapid expansion of space-time.
Explanation:
Cosmic inflation is a theory which states that in an interval of 10⁻³⁶ seconds to around 10⁻³³ seconds after the big bang there was a massive expansion.
According to the big bang theory the universe came to be from a singularity i.e., a point of infinite gravitational field. The universe is expanding this means that according to the conservation of energy the universe was expanding from the beginning.