Solution: We will apply Tcw = Tecw around an origin located at the top of the curb. Using this origin, the lever arm is zero for the force Fcurb. The position vector of the center of the wheel has a vertical component of (R- h). Use Pythagorean Theorem to calculate the horizontal component: = Xcenter R² - (R − h)² = √2Rh - h² Plug into Tcw = Tccw: F(Rh) mg (√√/2Rh - h²) = Wheel Over a Curb A wheel of mass m and radius R is pulled into a curb of height h by a horizontal force F as shown. mg. cur h The force F is just barely strong enough to lift the wheel off the ground (i.e. to make N = 0). 7 8 m 1.09kg R 0.307m h F 0.113m N (no answer) Correct Answer: 13.1 m R h F kg 0.318m 0.135m 17.3N Х (no answer) Correct Answer: 1.24