Answer:
(a) The horizontal ground reaction force 
(b) The vertical ground reaction force 
(c) The resultant ground reaction force 
Explanation:
Given
John mass , m = 65 kg
Horizontal acceleration , 
Vertical acceleration , 
(a) Using Newton's 2nd law in horizontal direction

=>
Thus the horizontal ground reaction force 
(b) Using Newton's 2nd law in vertical direction

=>
=>
Thus the vertical ground reaction force 
(c) Resultant ground reaction force is

=>
=>
Thus the resultant ground reaction force 
Answer: As per the question, a ray of light is incident on a surface and it is partly reflected and refracted. The incident light is an unpolarised light. The reflected light is partially polarised.
If the angle of incidence becomes equal to the Brester angle (polarising angle), then the reflected light is completely plane polarised.
Answer:
t = 3.48 s
Explanation:
The time for the maximum height can be calculated by taking the derivative of height function with respect to time and making it equal to zero:

where,
v₀ = initial speed = 110 ft/s
Therefore,

<u>t = 3.48 s</u>
You didn't attach the figure. Your text is incomplete. And you never got around to asking a question. Other than that, we're on it.
Answer:
carbon has four unpaired electrons in its valence shell . hydrogen having one unpaired electron in its valence shell comes to bond with carbon by sharing a pair of electrons .since carbon needs 4 electrons to be stable, 4 hydrogen atoms take part in the bond . It's a covalent bond because the difference between the electronegativity of carbon and hydrogen is quite small .