Astudent sits on a rotating stool holding two 1 kg objects. when his arms are extended horizontally, the objects are 1 m from the axis of rotation, and he rotates with angular speed of 0.76 rad/sec. calculate the final angular speed of the student.

The angular speed of the student is 1.144 rad/s.

Explanation:

Given that,

Mass of two objects = 1 kg

Distance = 1 m

Angular speed = 0.76 rad/s

Suppose The moment of inertia of the student plus stool is 3.0 kg-m² and is assumed to be constant. The student then pulls the objects horizontally to 0.40 m from the rotation axis.

We need to calculate the initial moment of inertia of the student & stool plus the two masses:

Using formula of moment of inertia

Put the value into the formula

We need to calculate the the final moment of inertia of the student & stool plus the two masses

Using formula of moment of inertia

Put the value into the formula

We need to calculate the angular speed

Using conservation of momentum

Put the value into the formula

Hence,The angular speed of the student is 1.144 rad/s.

chemical properties of thing

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation: