10.6 Torque  (Page 4/6)

Can a single force produce a zero torque?

Can a set of forces have a net torque that is zero and a net force that is not zero?

Can a set of forces have a net force that is zero and a net torque that is not zero?

In the expression $\overrightarrow{r}\times \overrightarrow{F}$ can $\left|\overrightarrow{r}\right|$ ever be less than the lever arm? Can it be equal to the lever arm?

Two flywheels of negligible mass and different radii are bonded together and rotate about a common axis (see below). The smaller flywheel of radius 30 cm has a cord that has a pulling force of 50 N on it. What pulling force needs to be applied to the cord connecting the larger flywheel of radius 50 cm such that the combination does not rotate?

The cylindrical head bolts on a car are to be tightened with a torque of 62.0 N $·\text{m}$ . If a mechanic uses a wrench of length 20 cm, what perpendicular force must he exert on the end of the wrench to tighten a bolt correctly?

(a) When opening a door, you push on it perpendicularly with a force of 55.0 N at a distance of 0.850 m from the hinges. What torque are you exerting relative to the hinges? (b) Does it matter if you push at the same height as the hinges? There is only one pair of hinges.

When tightening a bolt, you push perpendicularly on a wrench with a force of 165 N at a distance of 0.140 m from the center of the bolt. How much torque are you exerting in newton-meters (relative to the center of the bolt)?

What hanging mass must be placed on the cord to keep the pulley from rotating (see the following figure)? The mass on the frictionless plane is 5.0 kg. The inner radius of the pulley is 20 cm and the outer radius is 30 cm.

A simple pendulum consists of a massless tether 50 cm in length connected to a pivot and a small mass of 1.0 kg attached at the other end. What is the torque about the pivot when the pendulum makes an angle of $40\text{°}$ with respect to the vertical?

Calculate the torque about the z -axis that is out of the page at the origin in the following figure, given that $F_1=3\text{N},F_2=2\text{N},F_3=3\text{N},F_4=1.8\text{N}$ .

A seesaw has length 10.0 m and uniform mass 10.0 kg and is resting at an angle of $30\text{°}$ with respect to the ground (see the following figure). The pivot is located at 6.0 m. What magnitude of force needs to be applied perpendicular to the seesaw at the raised end so as to allow the seesaw to barely start to rotate?

A pendulum consists of a rod of mass 1 kg and length 1 m connected to a pivot with a solid sphere attached at the other end with mass 0.5 kg and radius 30 cm. What is the torque about the pivot when the pendulum makes an angle of $30\text{°}$ with respect to the vertical?

A torque of $5.00\times {10}^3\text{N}·\text{m}$ is required to raise a drawbridge (see the following figure). What is the tension necessary to produce this torque? Would it be easier to raise the drawbridge if the angle $\theta$ were larger or smaller?

A horizontal beam of length 3 m and mass 2.0 kg has a mass of 1.0 kg and width 0.2 m sitting at the end of the beam (see the following figure). What is the torque of the system about the support at the wall?

What force must be applied to end of a rod along the x -axis of length 2.0 m in order to produce a torque on the rod about the origin of $8.0\widehat{k}\text{N}·\text{m}$ ?

What is the torque about the origin of the force $(5.0\widehat{i}-2.0\widehat{j}+1.0\widehat{k})\text{N}$ if it is applied at the point whose position is: $\overrightarrow{r}=\left(\mathrm{-2.0}\widehat{i}+4.0\widehat{j}\right)\text{m?}$