WQ6.22 3/3 points (graded) Burglars are trying to haul a 1000kg safe up a ramp to their getaway truck using a rope. The ramp is tilted at angle 0 = 20°. The coefficients of static friction and kinetic friction between the safe and ramp are Ps = 0.80 and (4k = 0.50, respectively. Use g = 9.80 m/s2. (As exam preparation, compre your results to the tutorial questions from a few days ago, which was the same problem without friction.) a) What is the tension in the rope needed to set the safe into motion? Enter your answer in units of Newtons [N]. 10700 V 10700 b) If that tension is mintained after the motion starts, does the safe move with constant velocity or constant accoloration? O constant velocity constant acceleration > c) What is the resulting value of the velocity y or the acceleration a (depending on which you picked for part b)? Enter your answer in units of [m/s] or [m/s2]. 2.8 V 2.8
Q6.23 3/3 points (graded) A car rounds a curve on a flat road at constant speed. The car and driver have a combined mass of 950 kg and the curve has a radius of 66 m. The coefficient of static friction is /4s = 0.59. a) Draw a free-body diagram that shows all forces acting on the car. b) What is the maximum speed v with which the car can round the curve without skidding? Use g = 9.80 m/s. Enter your answer in [m/s]. V r 19.53 V Top view of car 19.53 Rear view of car c) If three passengers get in the car and bring the total mass to 1200 kg, what is the maximum speed v' with which the car can round the curve without sliding? Enter your answer in [m/s]. 19.53 19.53 d) What is the maximum speed with which the car can round a "banked' curve (the road has a slope as shown in the picture)? Assume that the radius of the curve is 66 m and the car has a total mass of 1200 kg. The road is icy and there is no friction. The angle 0 is 25°. Enter your answer in [m/s]. 17.37 V N cos 0 = w N sin 0 = F = Fnet 0 17.37