Answer:
1. True
2. False
3. True
Explanation:
Newton's 2nd law states that the net force exerted on an object is equal to the product between the mass of the object and its acceleration:
(1)
where
is the net force on the object
m is its mass
a is the acceleration
Furthermore, we know that acceleration is defined as the rate of change of velocity:
So let's now analyize the three statements:
1. A net force causes velocity to change: TRUE. Net force (means non-zero) causes a non-zero acceleration, which means that the velocity of the object must change.
2. If an object has a velocity, then we can conclude that there is a net force on the object: FALSE. The fact that the object has a velocity does not imply anything about its acceleration: in fact, if its velocity is constant, then its acceleration is zero, which would mean that the net force on the object is zero. So this statement is not necessarly true.
3. Accelerations are caused by the presence of a net force: TRUE. This is directly implied by eq.(1): the presence of the net force results in the object having a non-zero acceleration.
Answer:
Traits, evolution, adaptive
Physical Change
characteristic is the chemical bonds in the substance are unchanged. Because
a physical change is any change happens in an object but without involving
a change in its chemical substance. Example, Solid to liquid change or
also known as melting, liquid to gas change also known as evaporation, gas
to solid change also known as deposition, liquid to solid or
solidification, solid to gas or sublimation, and gas to liquid or
condensation. The physical form of a substance is change into a new form
but the chemical is unchanged.
Answer:
I = 0.5 A
Explanation:
Given: P=60 Watts, Voltage supply V = 120 Volts (for primary coil)
Solution:
we have P = V I
⇒ I = P /V = 60 Watts / 120 Volts
I = 0.5 A
Part (a):
1- Since the resistors are in series, therefore, the total resistance is the summation of the two resistors.
Therefore:
Rtotal = R1 + R2 = 3.11 + 6.15 = 9.26 ohm
2- Since the two resistors are in series, therefore, the current flowing in both is the same. We will use ohm's law to get the current as follows:
V = I*R
V is the voltage of the battery = 24 v
I is the current we want to get
R is the total resistance = 9.26 ohm
Therefore:
24 = 9.26*I
I = 24 / 9.26
I = 2.59 ampere
Part (b):
To get the voltage across the second resistor, we will again use Ohm's law as follows:
V = I*R
V is the voltage we want to get
I is the current in the second resistor = 2.59 ampere
R is the value of the second resistor = 6.15 ohm
Therefore:
V = I*R
V = 2.59 * 6.15
V = 15.9285 volts
Hope this helps :)
