I believe you are right. pH is the concentration of H+. Therefore the more acidic the more H+.
Answer:
54.6°
Explanation:
From law of reflection i=r.
So, construct the reflected ray at 55.7°degrees from the normal and let it fall on the other mirror.
Now draw the second normal at the point of incidence and again measure the angle of incidence, and draw the angle of reflection.
If you consider triangle AOB, one angle is ∠AOB=90°
and ∠OAB is 54.6°
From angle sum property third angle ie ∠ABO=180°-90°-54.6°=35.4°
So, the second incident angle will be 54.6°
Hence, the second reflected angle will be 54.6 degrees.
Answer:
The orbital period of the planet is 387.62 days.
Explanation:
Given that,
Mass of planet
Mass of star 
Radius of the orbit
Using centripetal and gravitational force
The centripetal force is given by


We know that,

....(I)
The gravitational force is given by
....(II)
From equation (I) and (II)

Where, m = mass of planet
m' = mass of star
G = gravitational constant
r = radius of the orbit
T = time period
Put the value into the formula





Hence, The orbital period of the planet is 387.62 days.
Answer B is the correct answer
We know that kinetic energy
, where m is the mass of object and v is the velocity of object.
In this case only velocity is the variable, mass remains constant.
So point having higher velocity has higher kinetic energy.
When it leaves the racket, the ball will be having a certain height, but just before it reaches the ground it will not having any height. So maximum velocity of ball is at that time when it reaches just above the ground.
So option B is the correct answer.