Answer:
Option (c) is correct.
Explanation:
Acceleration of an object is given by the formula as follows :

Where
u and v are initial and final velocity
t is time
(v-u) is also called the change in velocity
So, the acceleration of an object is equal to the rate of change of velocity. Hence, the correct option is (c) " Change in its velocity divided by the change in time".
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the friction force on two boxes is given as



Now we know by Newton's II law

so we have




Part b)
For block B we know that net force on it will push it forward with same acceleration so we have




Part c)
If Alex push from other side then also the acceleration will be same
So for box B we can say that Net force is given as




There is something wrong, 56 supposed to be 5/6 and 7575 is only 75 passengers.
So to solve for this problem:If an airplane carries 75 passengers and if it is 5/6 of the capacity which is x, then we can say that:
5/6 * x = 75
5x/6 = 75
5x = 75 x 6
5x = 450
5x/5 = 450/5
x = 90
The capacity of the airplane is 90
The question is incomplete and no options are given but the answer is;
The orbit of Mars is an ellipse,<span> is generally attributed to Kepler.
Kepler's first law states that; "</span><span>The orbits of the planets are ellipses, with the Sun at one focus of the ellipse.
</span>The planet at that point takes after and follow the ellipse in its orbit, which implies that the distance between Earth and Sun remove is continually changing as the planet goes around its orbit.