Answer:
270 m
Explanation:
We can find the distance travelled by the car by using the following suvat equation:

where
s is the distance travelled
u is the initial velocity
v is the final velocity
t is the time
For the car in this problem,
u = 0
v = 45 m/s
t = 12 s
Substituting into the equation, we find:

To solve this problem, it is necessary to apply the concepts related to force described in Newton's second law, so that
F = ma
Where,
m = mass
a = Acceleration (Gravitational acceleration when there is action over the object of the earth)
Torque, as we know, is the force applied at a certain distance, that is,

Where
F= Force
d = Distance
Our values are given as,



Since the system is in equilibrium the difference of the torques is the result of the total Torque applied, that is to say






Therefore the magnitude of the frictional torque at the axle of the pulley if the system remains at rest when the balls are released is 
Current = (voltage) / (resistance)
= (35 volts) / (1,400 ohms)
= 25 milliamperes
Answer:
The blue light has the highest energy.
Explanation:
Body that is hot enough emits light as consequence of its temperature. For example, an iron bar in contact with fire will start to change colors as the temperature increases until it gets to a blue color. That its know as Wien's displacement law, which establishes that the peak of emission for the spectrum will be displaced to shorter wavelengths as the temperature increases.
The same scenario described above can be found in the star, a star with higher temperature will have a blue color and one with lower temperature will have a red color.
(1)
The energy of each wavelength can be determined by means of the following equation:
(2)
but
, therefore:
(3)
Where h is the planck's constant and
is the frequency.
Notice that it is necessary to express the frequency in units of meters for a better representation of the energy.
⇒
⇒
Case for the bluest light:
Case for the reddest light:
Equation 3 show that if the wavelength is lower the energy will be greater (inversely proportional).
Hence, according with the result and what was explained above, the blue light has the highest energy.
Answer:
a) 323.4J
b) 0J
c) -323.4J
Explanation:
a) W=Fd
F=ma
solve for acc. using kinematics
v^2=vo^2+2a(x)
8.41=2a(12)
4.205=a(12)
0.35=a
F=(77)(0.35)
F=26.95N
W=26.95*12...... W=323.4J
b) No acceleration, thus no force, thus no work!
c) W=Fd
F=ma
find acc. using kinematics: v^2=vo^2+2a(x)
0=(2.9^2)+2a(12)
0=8.41+2a(12)
-8.41=2a(12)
-4.205=a(12)
-0.35=a
F=(77)(-0.35)
F=-26.95N
W=(-26.95)(12)
W=-323.4J
Yes, work can be negative!