alleryStart learning →You push perpendicular to a door with a force of 40 N at a distance of 0.800 m from the hinges. What torque do you exert about the hinges?
A50.0 N m
B0.020 N m
C32.0 N m
D3.20 N m
Answer & Solution
Correct answer: C. 32.0 N m
1. Use tau = r F sin(theta) with r = 0.800 m, F = 40 N and theta = 90 degrees.
2. sin(90 degrees) = 1, so the whole force is effective and tau = (0.800 m)(40 N)(1).
3. That gives tau = 32.0 N m about the hinges.
4. Dividing rather than multiplying by the distance gives 50.0 N m, a common slip.
_Source: OpenStax College Physics (CC BY 4.0), Ch 9 "Statics and Torque", section 9.2 The Second Condition for Equilibrium_
Keep practising Statics and Torque
Browse all Statics and Torque questions for B.Tech Robotics, or explore more Mechanics topics.
Related questions
A biceps muscle exerts 470 N to hold a forearm and a book whose combined weight is 63.7 N.In the arm, what does the triceps muscle do?Why do skeletal muscles such as the biceps and the triceps occur in opposing pairs?What is the mechanical advantage of a single ordinary pulley used to lift a load?A wheelbarrow has its load at a perpendicular lever arm of 7.50 cm from the wheel axle andWhat is a lever?How is the mechanical advantage of a simple machine defined?What does a simple machine do for its operator?