Question 7 of 10 Why are railroad tracks built with a flexible expansion and contraction joint? A. The two have equal coefficients of linear expansion. O B. The tracks have a smaller coefficient of linear expansion than the ground beneath. O C. The ground beneath has a larger coefficient of linear expansion than the tracks. O D. The tracks have a larger coefficient of linear expansion than the ground beneath.​

What is the measure of how much matter is in an object and that can be measured using a balance? a. height b. volume c. weight d. mass

An charge with mass m and charge q is emitted from the origin, (x,y)=(0,0). a large, flat screen is located at x=l. there is a target on the screen at y position y(h), where y(h) > 0. in this problem, you will examine two different ways that the charge might hit the target. ignore gravity in this problem. 1.assume that the charge is emitted with velocity v(0) in the positive x direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive y direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l. 2.now assume that the charge is emitted with velocity v(0) in the positive y direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive x direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l.

Amagnetic field applies forces on: a)static chargesb)moving chargesc)water flow