thats not correct. The formula for linear thermal expansion is: L = L_initial T where: L is the change in length, is the coefficient of linear expansion (in this case, for steel it's typically around 12 x 10^-6 /C), L_initial is the initial length (the length of the bridge in winter), and T is the change in temperature. In this problem, we're given: L_initial = 1,200 m (the length of the bridge in winter), T = 40C - (-35C) = 75C (the change in temperature from winter to summer), and = 12 x 10^-6 /C. Substituting these values into the formula, we get: L = L_initial T = 12 x 10^-6 /C 1,200 m 75C = 0.576 m So, the bridge is 0.576 m longer on a summer day when the temperature is 40C compared to a winter day when the temperature is -35C