Description: Exercise 22.45 A body of mass M , carrying charge Q , falls from re
ID: 2281217 • Letter: D
Question
Description: Exercise 22.45
A body of mass M, carrying charge Q, falls from rest from a height h (above the ground) near the surface of the Earth, where the gravitational acceleration is g and there is an electric field with a constant component E in the vertical direction.
a) Find an expression for the speed, v, of the body when it reaches the ground, in terms of M,g,Q, and E.
Please include a multiplication sign (*) to indicate that two variables are being multiplied.
b) The expression from part (a) is not meaningful for certain values of M, g, Q, and E. Explain what happens in such cases.
If the value of g?QEM is (Click For List)greaterless than zero, the argument of the square root is (Click For List)positive.negative. This means the value is (Click For List)non-realreal and the body (Click For List)rises.falls.does not move.
A body of mass M, carrying charge Q, falls from rest from a height h (above the ground) near the surface of the Earth, where the gravitational acceleration is g and there is an electric field with a constant component E in the vertical direction.
a) Find an expression for the speed, v, of the body when it reaches the ground, in terms of M,g,Q, and E.
Please include a multiplication sign (*) to indicate that two variables are being multiplied.
v =preview answer | change answer entry mode
b) The expression from part (a) is not meaningful for certain values of M, g, Q, and E. Explain what happens in such cases.
If the value of g?QEM is (Click For List)greaterless than zero, the argument of the square root is (Click For List)positive.negative. This means the value is (Click For List)non-realreal and the body (Click For List)rises.falls.does not move.
Explanation / Answer
a) conservation of energy
m g h - q E h = 1/2 mv^2
v = sqrt( 2( m g h - q Eh)/m)
v = sqrt(2 g h - 2 q E h/m)
b) g - q E/m less than zero than the argument is negative
value is negative and th ebody never hits the gorund