Answer:
Explanation:
The work function of the metal corresponds to the minimum energy needed to extract a photoelectron from the metal. In this case, it is:
So, the energy of the incoming photon hitting on the metal must be at least equal to this value.
The energy of a photon is given by
where
h is the Planck's constant
c is the speed of light
is the wavelength of the photon
Using 
and solving for , we find the maximum wavelength of the radiation that will eject electrons from the metal:
And since
1 angstrom = 
The wavelength in angstroms is
Answer:
The pendulum frequency is (c) the same, or very close to it
Explanation:
The simple pendulum corresponds to a simple harmonic movement, to reach this approximation in the expression of the force the sine of the angle (θ) approaches an angle value, this is only true for small angles, generally less than 15º
Sine (15th) = 0.2588
The angle in radians is 15º π / 180º = 0.26180.2588 / 0.2618
The difference between these two values is less than 1.2%
for smaller angle the difference is reduced more
Therefore, the period for both the 5º and 10º angles is almost the same
The resultant vector can be determined by the component vectors. The component vectors are vector lying along the x and y-axes. The equation for the resultant vector, v is:
v = √(vx² + vy²)
v = √[(9.80)² + (-6.40)²]
v = √137 or 11.7 units
Newtons law of gravitation is called the universal law of gravitation because it is applicable for all masses at all distances, independent of the medium.
