A pendulum consists of an object of mass 1.07 kg that hangs at the end of a massless bar, a distance 1.14 m from the pivot point. Calculate the magnitude of the torque due to gravity about the pivot point if the bar makes an angle of 22° with the vertical.
torque = weightpendulum*cos22*1.14
= 1.07 kg x cos22 x 1.14
= -1.22 kg
= 1.22 kg
Why am I getting this answer incorrect?
I don't see g = 9,8 m/s^2 in your calculations. Torque is caused by GRAVITY in this case.
The formula for torque due to gravity is actually given by the equation:
torque = weight * lever arm
where weight is the force due to gravity acting on the object and the lever arm is the perpendicular distance from the pivot point to the line of action of the weight.
In this case, to find the torque, we need to find the lever arm. The lever arm is the distance between the pivot point and the center of mass of the object, which is given as 1.14 m.
The weight of the object can be calculated using the equation:
weight = mass * acceleration due to gravity
where the acceleration due to gravity is approximately 9.8 m/s^2.
So, the weight of the object is:
weight = 1.07 kg * 9.8 m/s^2 = 10.526 N
Now, we can calculate the torque using:
torque = weight * lever arm
torque = 10.526 N * 1.14 m = 11.986 Nm
Therefore, the correct answer for the magnitude of the torque due to gravity about the pivot point is 11.986 Nm.