Answer: A
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Answer: The speed necessary for the electron to have this energy is 466462 m/s
Explanation:
Kinetic energy is the energy posessed by an object by virtue of its motion.

K.E= kinetic energy = 
m= mass of an electron = 
v= velocity of object = ?
Putting in the values in the equation:


The speed necessary for the electron to have this energy is 466462 m/s
The equation we use is mλ=dsinθ for intensity maximas. We are given at the first maximum (m=1), it occurs at 17.8 degrees. Thus we can solve for d by substituting known values into our equation.
(1) (632.8*10^-9m)=dsin(17.8) => d = 2.07*10^-6m
Next we want to find the angle at the second maximum (m=2) so we need to solve for θ.
(2) (632.8*10^-9m) = (2.07*10^-6m)sinθ
θ=37.69 degrees
Hopes this helps!
P.S. I hope this is right. If not sorry in advance.
Answer:
Work = 6912 joules
Explanation:
Non-conservative forces are dissipative forces such as friction or air resistance. These forces take energy away from the system as the system progresses, energy that you can't get back. These forces are path dependent; therefore it matters where the object starts and stops.
Total mass = 40 + 8 = 48kg
Initial speed u= 6 m/s
Final speed v = 3*initial
Final speed v = 3* 6 = 18 m/s
Distance s = 15
Acceleration a is?
V² = U² + 2aS
18² = 6² + 2a*15
324 = 36 + 30a
324-36= 30a
288 = 30a
288/30 = a
9.6= a
Force = mass* acceleration
Force = 48*9.6
Force = 460.8N
Work = force*distance
Work = 460.8*15
Work = 6912 joules