Answer:
Force, F = 187.42 N
Explanation:
It is given that,
Mass of boy, m = 30 kg
Acceleration due to gravity, 
Radius of curvature of the roller coaster, r = 15 m
Speed of the car, v = 7.3 m/s
The force acting on the boy are force of gravity and the centripetal force. The net force acting on him is as follows :



F = 187.42 N
So, he press against the seat with a force is 187.42 N. Hence, this is the required solution.
C: reflected
because the sun shines on the water when u look into the water u can see the sun
Answer:

Explanation:
The charge transferred charge Q= −10nC = -10*10-9 C
Charge of a electron : 
Number of electrons transferred: 
The answer is A: Core --> Mantle --> Crust.
Core: The earth's core is the center of the earth, which would ultimately be the deepest. The core is made up of alloy, which is a mixture of many medals, such as iron and nickel.
Mantle: The earth's mantle is the layer between the earths crust and core. Often made of silicate rocks.
Crust: The earth's crust is the outer-most of the three options. Usually made of up different types of rocks.
Answer:
b 2 only
Explanation:
The mass of an electron is 9.10938356 × 10⁻³¹ kilograms while the mass of a proton is 1.6726219 × 10⁻²⁷ kilograms. It can be seen that a proton is heavier than an electron.
Atoms do not always have the same number of neutrons and protons. For, example ¹³C has 6 protons and 7 neutrons.
Atoms do have most of the mass concentrated at the center called the nucleus. The nucleus has protons and neutrons. As protons have positive charge and neutrons have no charge the nucleus has a positive charge.