Answer:
3.8 kg
Explanation:
The torque, <em>τ</em>, due to the force, <em>F</em>, is given by

where <em>r</em> is the radius.
This torque is also given by

where <em>I</em> and <em>α</em> are respectively the moment of inertia and the angular acceleration.
For a solid disk, its moment of inertia for an axis though its centre and perpendicular to its face is given by

where <em>m</em> is its mass and <em>r</em> is its radius.
Hence, we have


Answer:

Explanation:
first ball rolls on the porch by total distance

Then again it will move on horizontal floor

also in vertical direction it will drop down

so we have



so magnitude of net displacement of the ball is given as


Answer:
Flow rate 2.34 m3/s
Diameter 0.754 m
Explanation:
Assuming steady flow, the volume flow rate along the pipe will always be constant, and equals to the product of flow speed and cross-section area.
The area at the well head is

So the volume flow rate along the pipe is

We can use the similar logic to find the cross-section area at the refinery

The radius of the pipe at the refinery is:



So the diameter is twice the radius = 0.38*2 = 0.754m
Assuming all the landmasses continue to move towards a sort of epicenter, large mountain ranges would appear in Africa and Europe.