A because the girl in that instant is not moving up or down so
( up forces)=(down forces )
The up forces is the tension of the rope and down forces us mg -the gravitational force on the girl by the earth
The motor effect is the term used when a current-carrying wire in the presence of a magnetic field experiences a force.
Explanation:
According to formula
g = GM/R^2
when mass is halved the value of g becomes half but when radius is halved the value of g increases 4 times.
As a result of both value of g becomes twice.
The formula for the density of a substance expressed in mass and volume is rho = mass/volume or p = m/v. Rearranging the formula to isolate volume gives the formula v = m/p. To solve for the problem given, this formula must be used. This gives a solution of:
v = m/p = 250 g/ 968 g/cm^3 = 0.258 cm^3 of sodium
The statement is true because an object will remain not moving until an external force is applied into. so in order to move an object external force should be applied. for example an object fell down, even no one pushes it pulls it, but the force due to gravity is acting on it so there is still a force acting on it.