- ' eness 65) Using your example to the two questions above comment on the relative effectlv of friction versus banked roads in keeping you safe on the road! . . has 66) Now consider the same car and the same curve but this time the banked road also ' t static friction. What is the maximum speed the car can go aroond the turn withou sliding? 67) A pilot is flying a jet. Part of the motion can be considered as a vertical circle with a; radius of curvature of 765m. The plane is flying with 3 Speed MM What is t 9 force of the seat on the pilot at the bottom of the turn. 68) A roller coaster slides on a frictionless track. The coaster starts at height h above ground level, and then once it reaches ground level goes around a vertical circle of radius R. How large must h be i in terms of B) so that the coaster stays on the track at all times? 69) A toboggan slides down a hill with no friction. The hill is at a slope of W and has a total distance of 120 m. What is the speed of the toboggan at the bottom of the hill? Now suppose there is kinetic friction with friction coefficient 0.3. What IS the speed at the base of the hill and how far past the base of the hill will the toboggan travel before coming to a full stop? 70) A 2000kg car slows from 80 km/hr to 70 km/hr without braking. Find i) the frictional force , and ii) the power required to keep the car moving at 80 kmfhr 71) A car of mass 2000 kg is travelling east at a speed of 25 km/hr, when it collides with a second car travelling north of mass 1000 kg at a speed of 50 km/hr. After the collision the cars stick together and move as one. i) what is the final speed of the cars? ii} what direction is the nal velocity? iii) how much kinetic energy was lost in the collision? 72) A person stands at the end of a in canoe initially at rest in the water. The person walks from one side of the canoe to the other, how much does the centre of mass of the canoe change? 73) A wheel rotating at 200 rpm undergoes constant angular acceleration for 205. After that time the wheel his rotating at 500 rpm. i) what is the angular acceleration {in correct units}? ii) how many rotations does the when make in that 205? if the wheel is a disk mass 1 kg and R 0.2m, what torque is required? 74) An electric motor is providing constant torque to a solid disk with M=3kg, R=8 cm. There is a frictional torque opposing the rotation. It takes 45 for the disk to go from rest to 600 rpm, and then when the motor is turned off, 425 for it to come to rest again. Find the torque provided by the motor and the frictional torque