Answer:
3. both are true.
Explanation:
Energy increses with decrease in wavelenght.
For photoemission to occur, a threshold energy barrier must be broken.
Higher energy means more electrons will be emmited.
The electrons emmited will posses energy that is less than the incident energy by the value of the threshold energy.
So the higher the energy, the higher the energy possessed by the electrons.
Answer:
unit (v) = [ -0.199 i - 0.8955 j + 0.39801 k ]
Explanation:
Given:
v = (-23.2, -104.4, 46.4) m/s
Above expression describes spacecraft's velocity vector v.
Find:
Find unit vector in the direction of spacecraft velocity v.
Solution:
Step 1: Compute magnitude of velocity vector.
mag (v) = sqrt ( 23.2^2 + 104.4^2 + 46.4^2)
mag (v) = 116.58 m/s
Step 2: Compute unit vector unit (v)
unit (v) = vec (v) / mag (v)
unit (v) = [ -23.2 i -104.4 j + 46.4 k ] / 116.58
unit (v) = [ -0.199 i - 0.8955 j + 0.39801 k ]
Answer:
(A) Speed will be 
(b) Change in kinetic energy =
Explanation:
We have given mass of proton 
Acceleration of the proton 
Initial velocity u =
m/sec
Distance traveled by proton s = 3.90 cm = 0.039 m
(a) From third equation of motion we know that



(b) Initial kinetic energy 
Final kinetic energy 
So change in kinetic energy 
The speed of something in any given direction.
Answer:
For sound waves to travel, there is a requirement of medium and density of the medium is considered to be one of the factors on which the speed of sound depends. When the medium is dense, the molecules in the medium are closely packed which means that the sound travels faster.
Explanation: