Answer:
(a) The "angular speed" is 5.88 rad/s.
Explanation:
Given values,
The length of the bar is L = 2m
The weight of the bar is w = 90 N
The metal bar is hanging vertically from the ceiling by a frictionless pivot
The mass of the ball is m = 3kg
The distance between the ceiling and the ball is d = 1.5m


(a) Calculating the angular speed:




The angular speed is 5.88 rad/s.
(b) The "angular momentum" is conserved because the torque is not exerted by "the pivot" on the system about the "axis of rotation" but the "linear momentum" is not conserved because "the pivot" exerts a "vertical" and a "horizontal force" on the system during the collision.
D - performance measures.
If Dan is starting his plant, he will want to see if his new workers are performing the way he wants them to perform in order to meet the requirements for the amount of product he would like to produce on a weekly basis. This can be only done if he will pay special attention to different performance measures.
Answer:
Work done by the spring is negative
Explanation:
We can answer this question by thinking what is the force acting on the box.
In fact, the force acting on the box is the restoring force of the spring, which is given by Hooke's Law:

where
k is the spring constant
x is the displacement of the box with respect to the equilibrium position of the spring
The negative sign in the equation indicates that the direction of the force is always opposite to the direction of the displacement: so, whether the spring is compressed or stretched, the force applied by the spring on the box is towards the equilibrium position.
The work done by the restoring force is also given by

where
F is the restoring force
x is the displacement
is the angle between the direction of the force and the displacement
Here we know that the force is always opposite to the displacement, so

Which means that the work done by the spring is always negative, since the direction of the restoring force is always opposite to the direction of motion.
Answer:
Option (d)
Explanation:
The electrons in a conductor moves with the drift velocity when the electric current is flowing through the conductor.
The drift velocity is due to the applied electric field across the conductor.
Answer:
Electric flux in a) , b) and c) is same which is 0.373 × 10 ⁶ N m²/C
Explanation:
given,
surface charge (q) = 3.3 × 10⁻⁶ C
to calculate electric flux = ?
a) radius = 0.76 m
area of sphere = 4 π r²
electric flux = 

electric flux = 
flux = 0.373 × 10 ⁶ N m²/C
electric flux in the other two cases will also be same as electric flux is independent of area
so, Electric flux in a) , b) and c) is same which is 0.373 × 10 ⁶ N m²/C