equation 10.18. this equation cannot be applied to many-electron atoms. one way to modify it for the more complex atoms is to replace z with ^z 2 σh, where z is the atomic number and σ is a positive dimensionless quantity called the shielding constant. consider the helium atom as an example. the physical significance of σ is that it represents the extent of shielding that the two 1s electrons exert on each other. thus, the quantity ^z 2 σh is appropriately called the effective nuclear charge. calculate the value of σ if the first ionization energy of helium is 3.94 × 10−18 j per atom. ^in your calculations, ignore the minus sign in the given equation. h

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.

an obstruction

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft