Answer:
Lithium
Explanation:
The equation for the photoelectric effect is

where
is the energy of the incident photon, with
h being the Planck constant
c is the speed of light
is the wavelength of the photon
is the work function of the metal (the minimum energy needed to extract the photoelectron from the metal)
is the maximum kinetic energy of the emitted photoelectrons
In this problem, we have
is the wavelength of the incident photon
is the maximum kinetic energy of the electrons
First of all we can find the energy of the incident photon

Converting into electronvolts,

So now we can re-arrange the equation of the photoelectric effect to find the work function of the metal

So the metal is most likely Lithium, which has a work function of 2.5 eV.
Answer:
The distance away the center of the earthquake is 1083.24 km.
Explanation:
Given that,
Speed of transverse wave = 9.1\ km/s
Speed of longitudinal wave = 5.7 km/s
Time = 71 sec
We need to calculate the distance of transverse wave
Using formula of distance

....(I)
The distance of longitudinal wave
....(II)
From the first equation

Put the value of t in equation (II)




Hence, The distance away the center of the earthquake is 1083.24 km.
Answer: Kinetic frictional force = 23.76N
Explanation: Please see the attachments below
Let us first know the given: Tennis ball has a mass of 0.003 kg, Soccer ball has a mass of 0.43 kg. Having the same velocity at 16 m/s. First the equation for momentum is P=MV P=Momentum M=Mass V=Velocity. Now let us have the solution for the momentum of tennis ball. Pt=0.003 x 16 m/s= ( kg-m/s ) I use the subscript "t" for tennis. Momentum of Soccer ball Ps= 0.43 x 13m/s = ( km-m/s). If we going to compare the momentum of both balls, the heavier object will surely have a greater momentum because it has a larger mass, unless otherwise the tennis ball with a lesser mass will have a greater velocity to be equal or greater than the momentum of a soccer ball.