Answer:
(a) P = 459.055 N.
(b) the refrigerator tips.
Explanation:
Given, the angle of ramp is 20°.
When the weight of refrigerator is resolved in directions parallel and perpendicular to ramp, 75×g×sin(20°) and 75×g×cos(20°).
⇒ normal contact force is 75×g×cos(20°).
⇒ frictional force is 0.3×75×g×cos(20°) = 207.414 N
so, total opposite force is 207.414 + 75×g×sin(20°) = 459.055 N.
so, the force needed is P = 459.055 N
And as the moment due to both opposite force and P force are in same direction the refrigerator tips rather than just sliding.
Answer:
The weight acting upon a object
Explanation:
That's the Cosmic Microwave Background (CMB). (D)
It doesn't "provide evidence for the ... Theory". The Big Bang theory is the best explanation (so far) for the CMB and a lot of other observations.
Evidence isn't used to prove theories. Theories are attempts to explain evidence.
Answer:
as the period decreases, the frequency and energy of the wave increase
Explanation:
Electromagnetic waves are oscillations of the electric and magnetic fields, described by maxwell's equations, the speed of the wave is called the speed of light
c = λ f
E = E cos (kx - wt)
Angular velocity is related to frequency and period.
w = 2π f = 2π / T
Let's analyze what happens when the wave period decreases, angular velocity and frequency increase.
This increase in frequency is reflected with the Planck equation in wave energy
E = h f
Therefore the wave carries more energy and can lead to stronger interactions with matter.
In summary, as the period decreases, the frequency and energy of the wave increase
Well potential energy is energy possessed by an object of by the position it's in. For example when you hold back a bow and arrow, but before you shoot it you are containing energy by holding the arrow back. So when you start the magnetic generator (pull or turn to start it) before using it for its purpose that is potential energy. I hope this helps.
