Question

A pizza delivery car is travelling around a corner of radius 50m at 60km/h. The road is level, however at this speed the car tilts over on its suspension at an angle of 5º. The 2kg sign on their roof is held on by magnets that provide an attractive force of 50N 50m [PIZA Neglecting wind resistance; (a) Draw a free body diagram of the 'Pizza' sign showing all forces that act. [2 marks] (b) Calculate the magnitude of the acceleration of the sign. [2 marks] (C) Calculate the magnitude of the friction force required for the sign to remain in place on the roof of the car. [4 Marks] (d) What coefficient of friction is required for the sign to remain in place? [2 Marks]

Answer 1

3600 16.67 5 0N (Magnetic farce). (1) centrifugal force on to sign = mv Given we rass=2kg va velocity = 60 x3 m/s = 16 R = radius = 50m Ik 50 centrifugal force on sign = 2X(6.67) (2X9.8) N( Weight) 50 - 11-12 N Free For furetinal toute centeifugal force will act away from centre of concle and parallel to of road. weight = 4x9.8) N will act vertical down. magnetic face = SON will set go to the verticale, (3) Acceleration due to centrifugal face will be = v= 26.60 Arceberetion = 5.56 m/87 po 50 Ich fictional force will act so to the hollrontal as shown in figan to by force balance in vertical dilection. .21 900 CN Fy (8 159 +50 sin(59 = 11.12 (2x9.8). Fy (815) +5060.087) = 11.12 Jo N (d) Fy = 11.12-4.36 – 6.79 N 10159 Fo= 6.79 friciond free = u xC Normal face) fo= 4(50 + 8x9.8) (oss + 11.12 (498) = 68.56) 6.29 - 1 168.56) u= 6.29 = 0.099 (M = 0.1)