Work = Force * distance
Work = 20 N * 10 m = 200 Nm
Work = 200 Joules.
Answer:
Vf = 3.67 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.

where:
Vf = final velocity [m/s]
Vi = initial velocity = 4.3 [m/s]
a = acceleration or desacceleration = 0.5 [m/s²]
x = distance = 5 [m]
Note: The negative sign in the above equation means that the velocity of the ball is decreasing (desacceleration).
Now replacing:
Vf² = (4.3)² - (2*0.5*5)
Vf² = 18.49 - 5
Vf² = 13.49
using the square root, we have.
Vf = 3.67 [m/s]
Repeat the experiment to make sure it gives the same results.
Hope i helped ; )
Answer:
Frequency
Explanation:
Photons are the packet of energy. They are massless and chargeless particles. They travel in the vacuum with the speed of light. The energy of photon is given by :

Where
h = Planck's constant
= frequency of photon
Or 
c = speed of light
= wavelength of photon
From the above equation, it is clear that the energy of photon is directly proportional to its frequency.