Answer: The correct answer is balanced force.
Explanation:
Balanced forces are balanced when the forces are acting equal in magnitude but opposite in direction. The balanced forces will not cause change in the speed of the object.
Unbalanced forces are unbalanced when the forces acting on the object are not equal in magnitude. The combined force is the difference between the forces. It will cause the change in the speed of the body.
Therefore, forces that are equal in size but opposite in direction are balanced.
Acceleration is the rate of change of velocity of an object. Thus when the velocity ( direction or magnitude) of an object changes, we say that the particle is accelerating. Mathematically it is written as
a= 
The units of acceleration are m/s²
Acceleration can be positive or negative. If the velocity of an object increases, we call that as positive acceleration and if the velocity of an object decreases, we call that as the negative acceleration.
Answer:
, 
(Northeast)
Explanation:
Let consider that owner has the resultant direction of the momentums from the dog and the cat. First, the momentum of the owner is:
![\|\vec p \| = \sqrt{\left[(27.4\,kg)\cdot \left(2.19\,\frac{m}{s} \right)\right]^{2}+\left[(7.19\,kg)\cdot \left(2.78\,\frac{m}{s} \right)\right]^{2}}](https://tex.z-dn.net/?f=%5C%7C%5Cvec%20p%20%5C%7C%20%3D%20%5Csqrt%7B%5Cleft%5B%2827.4%5C%2Ckg%29%5Ccdot%20%5Cleft%282.19%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%5Cright%29%5Cright%5D%5E%7B2%7D%2B%5Cleft%5B%287.19%5C%2Ckg%29%5Ccdot%20%5Cleft%282.78%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%5Cright%29%5Cright%5D%5E%7B2%7D%7D)
The speed of the owner is:
Lastly, the direction of the owner is:
![\alpha = \tan^{-1}\left[\frac{(27.4\,kg)\cdot \left(2.19\,\frac{m}{s} \right)}{(7.19\,kg)\cdot \left(2.78\,\frac{m}{s} \right)} \right]](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%5Ctan%5E%7B-1%7D%5Cleft%5B%5Cfrac%7B%2827.4%5C%2Ckg%29%5Ccdot%20%5Cleft%282.19%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%5Cright%29%7D%7B%287.19%5C%2Ckg%29%5Ccdot%20%5Cleft%282.78%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%5Cright%29%7D%20%5Cright%5D)
(Northeast)
In accordance with the definition of density as r = m/V, in order to determine the density of
matter, the mass and the volume of the sample must be known.
The determination of mass can be performed directly using a weighing instrument.
The determination of volume generally cannot be performed directly. Exceptions to this rule
include
· cases where the accuracy is not required to be very high, and
· measurements performed on geometric bodies, such as cubes, cuboids or cylinders, the volume
of which can easily be determined from dimensions such as length, height and diameter.
· The volume of a liquid can be measured in a graduated cylinder or in a pipette; the volume of
solids can be determined by immersing the sample in a cylinder filled with water and then
measuring the rise in the water level.
Because of the difficulty of determining volume with precision, especially when the sample has a
highly irregular shape, a "detour" is often taken when determining the density, by making use of the
Archimedean Principle, which describes the relation between forces (or masses), volumes and
densities of solid samples immersed in liquid:
From everyday experience, everyone is familiar with the effect that an object or body appears to
be lighter than in air – just like your own body in a swimming pool.
Figure 3: The force exerted by a body on a spring scale in air (left) and in water (right)
Refractive index is the ration of sin i to sin r where i is the incident angle and r is the refraction angle.
Therefore, refractive index = sin 79.5 / sin 39.6
= 1.542
The refractive index may be given by the ratio of refractive index of medium 2 to refractive index of medium 1.
Therefore, 1.542 = n/1.0003
n = 1.5425
≈ 1.54
Medium 2 is sodium chloride, refractive index of 1.54
