BEST PRACTICE Torque and Moment of Inertia

A bolt is to be tightened with a torque of 8.0 Nm. If you have a wrench that is 0.35 m long, what is the least amount of force (in newton) you must exert? Express the answer in 2 significant figures. No need to write the unit.

What is the torque (in newton-meter) on a bolt produced by a 15-N force exerted perpendicular to a wrench that is 25 cm long, as shown in the figure? Express the answer in 2 significant figures. No need to write the units.

A toy consisting of two balls, each 0.45 kg, at the ends of a 0.46-m-long, thin, lightweight rod is shown in the figure. Find the moment of inertia of the toy about one end of the rod.

• 0.048 kg-m²

• 0.19 kg-m²

• 0.21 kg-m²

• 0.095 kg-m²

A toy consisting of two balls, each 0.45 kg, at the ends of a 0.46-m-long, thin, lightweight rod is shown in the figure. Find the moment of inertia of the toy about the center of the rod.

• 0.048 kg-m²

• 0.19 kg-m²

• 0.21 kg-m²

• 0.095 kg-m²

A bicycle wheel with a radius of 38 cm is given an angular acceleration of 2.67 rad/s² by applying a force of 0.35 N on the edge of the wheel. What is the wheel’s moment of inertia in kg-m²? Express the answer in 3 decimal places. No need to write the units.