Answer to Question #155121 in Physics for Arvin Shopon

Question

a) The student helps his parents to change the tires of the car. How much torque can a student produce with a 30 cm long ring iron when pushing the iron down with its full weight to open the tire mounting bolt? The student weighs 60 kg. 

b) If the tire mounting bolt does not open, a tube can be used as an extension arm, which is placed as an extension of the ring iron arm. How much torque does the student achieve if the arm of the ring iron is now 130 cm long?

Answer 1

a) The torque that the student can produce is

$$\tau=Fd=mgd=60\cdot9.8\cdot0.3=176.4\text{ N m}$$

b) With a 130 cm-long arm, the torque increases (we can use the same equation):

$$\tau=60\cdot9.8\cdot130=764.4\text{ N m}.$$