Answer:
C. Dark Matter
Explanation:
Dark matter is estimated to make up 90 percent of the mass of the galaxy.
The dark matter (as astronomers have come to call the invisible material) extends to a distance of at least 200,000 light-years from the center of the Galaxy.
Answer:
a) The velocity of the car is 7.02 m/s and the car is approaching to the police car as the frequency of the police car is increasing.
b) The frequency is 1404.08 Hz
Explanation:
If the police car is a stationary source, the frequency is:
(eq. 1)
fs = frequency of police car = 1200 Hz
fa = frequency of moving car as listener
v = speed of sound of air
vc = speed of moving car
If the police car is a stationary observer, the frequency is:
(eq. 2)
Now,
fL = frequecy police car receives
fs = frequency police car as observer
a) The velocity of car is from eq. 2:
b) Substitute eq. 1 in eq. 2:
Answer:
The temperature of the coil will increase (over heating will occur)
Explanation:
This overheating generally occurs when the motor is overloaded, when a bearing seizes up, when something locks the motor shaft and prevents it from turning, or when the motor simply fails to start properly.
Back emf is zero when the motor is not turning, and it increases proportionally to the motor's angular velocity. As the motor turns faster and faster, the back emf grows, always opposing the driving emf, and reduces the voltage across the coil and the amount of current it draws.
Answer:
Changes in the object's momentum (answer D)
Explanation:
A net force will cause an object to change its velocity, and that will affect the object's momentum, which is defined by the product of the object's mass times its velocity.
So, select the last option (D) in the given list.
Acceleration = ms^(-1)
= 60/4
=15 ms with the power of -1
