Isn't velocity Distance over time? if the degree isn't adding resistance it should be 4000 ÷ 20 which gives you 200mps ("per second") which is the velocity without resistance.
Question is missing. Found on google:
<em>"Part A What is the acceleration of the ball? Express your answer to two significant figures and include the appropriate units. </em>
<em>Part B
</em>
<em>What is the net force on the ball during the hit? </em>
<em>Express your answer to two significant figures and include the appropriate units."</em>
Solution:
A) 
The acceleration of the ball is given by

where
v = 12 m/s is the final velocity
u = 0 is the initial velocity (the ball is stationary)
t = 2.0 ms = 0.002 s is the time of contact
Substituting,

B) 
The force on the ball can be found by using Newton's second law:

where
m = 140 g = 0.14 kg is the mass of the ball
is the acceleration
Substituting,

Answer:
i. 0.34
ii. 0.4
iii. 1700 w/m²
iv. 2211.36 w/m²
Explanation:
Given that
Irradiation of the plate, G = 2500 w/m²
Reflected rays, p = 500 w/m²
Emissive power, E = 1200 w/m²
See attachment for calculations
You would probably have a low frequency due to how much the wavelength is spread out.
Answer:
Explanation:
We shall take the help of vector form of displacement . Taking east as i and north as j
4.0m N = 4 j
7.5 m E = 7.5 i
6.8 m S = - 6.8 j
3.7 m E, = 3.7 i
3.6 m S = - 3.6 j
5.3 m W = - 5.3 i
3.7 m N, = 3.7 j
5.6 m W = - 5.6 i
4.4 m S = - 4.4 j
4.9 m W = - 4.9 i
Total displacement = 4j +7.5 i -6.8j+3.7i-3.6j-5.3i+3.7j-5.6i-4.4j-4.9i
= -4.6 i -7.1 j
magnitude of displacement = 
= 8.46 m
Direction
Tanθ = 7.1/ 4.6
θ = 57⁰ south of west .
distance walked = 4+7.5 +6.8+3.7+3.6+5.3+3.7+5.6+4.4+4.9
= 49.5 m