Answer:
An acceleration of 5m/s^2 means that the velocity of a body is increasing by 5m/s per second in a certain direction
Explanation:
(a) 
The gravitational potential energy of the two-sphere system is given by
(1)
where
G is the gravitational constant
is the mass of sphere A
is the mass of sphere B
r = 1.8 m is the distance between the two spheres
Substitutign data in the formula, we find

and the sign is negative since gravity is an attractive force.
(b) 
According to the law of conservation of energy, the kinetic energy gained by sphere B will be equal to the change in gravitational potential energy of the system:
(2)
where
is the initial potential energy
The final potential energy can be found by substituting
r = 1.80 m -0.60 m=1.20 m
inside the equation (1):
U=-\frac{(6.67\cdot 10^{-11})(94 kg)(100 kg)}{1.2 m}=-5.22\cdot 10^{-7} J
So now we can use eq.(2) to find the kinetic energy of sphere B:

Answer:
The distance of car form the mirror is 330 cm.
Explanation:
height of object, h = 140 cm
height of image, h' = 14 cm
radius of curvature, R = 60 cm
focal length, f = R/2 = + 30 cm
Let the distance of image is v and the distance of object is u.

Use the formula of focal length

Answer:
The correct option is: d. Fiber-optic
Explanation:
A fiber-optic cables or an optical-fiber cable is a cable that is composed of a bundle of optical fibers. These cables are used for transmitting information or digital signals over long distances.
Each optical fiber in an optical-fiber cable is individually coated with a protective plastic cover and contained in a protective tube. Therefore, an optical-fiber cable is not affected by any electromagnetic interference or radio frequency interference.
∆S>_closed integral of dQ/T
There are many equations for different situations of entropy but this is a general one