Complete Question
The complete question is shown on the first uploaded image
Answer:
The correct option is B
Explanation:
The number of alphabet is n= 4 (a , b , c , d )
Generally the total number of string of length 10 over the 4 alphabets is

Gnerally the number of string of length 10 that does not include b is
Generally the number of strings of length 10 over the 4 alphabets that have at least one alphabet b somewhere in the string is

=> 
Answer:
All these statement are true
Explanation:
Gravity will be acting like a centripetal force for the circular motion of object around earth, which makes it perpendicular to the velocity vector. In the case of elliptical motion, gravity can still be divided into 2 vectors, one parallel and the other perpendicular to the velocity. At the nearest point in elliptical motion, gravity is directly perpendicular to velocity just like in circular motion. At the farthest point, the potential energy is minimized and has been converted into kinetic energy. Therefore at this point the speed is greatest.
When a mass of 8 kg is located on the Earth's surface, the magnitude of each of
the gravitational forces attracting the mass and the Earth toward each other is
(mass) x (acceleration of gravity on Earth) =
(8.0 kg) x (9.81 m/s²) =
78.48 kg-m/s² = <em>78.48 newtons </em>(about 17 pounds 10.2 ounces)
Aggregat 4, Aggregat 4, Aggregat 4, Aggregat 4,