Answer:
a. 8p
Explanation:
We are given that
Radius of hollow sphere , R1=R
Density of hollow sphere=
After compress
Radius of hollow sphere, R2=R/2
We have to find density of the compressed sphere.
We know that


Therefore,
Volume of sphere=
Using the formula



Hence, the density of the compressed sphere=
Option a is correct.
<em>Kinetic Energy</em>
=><em><u>It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.</u></em>
<em>Potential</em><em> </em><em>Energy</em><em> </em>
<u><em>=</em><em>></em><em>potential energy is the energy held by </em></u><em><u>an</u></em>
<em><u> object because of its position relative to </u></em><em><u>other</u></em>
<em><u> objects, stresses within itself, its </u></em><em><u>electric</u></em>
<em><u> charge, or other factors.</u></em>
<h2>Difference:</h2>
=>Potential energy is a <u>stored</u> energy on the other hand kinetic energy is the energy of an object or a system's particle in <em><u>Motion</u></em>.
Answer:
Yes. Walking is controlled falling because you need to let go in order to move forward. If you never let your foot fall, your movements would be stilted and robotic. And according to medical engineers," When we walk normally we are constantly correcting tiny falls to keep ourselves stable."
Explanation:
Answer:
Zero
Explanation:
Net force can be defined as the vector sum of all the forces acting on a body or an object i.e the sum of all forces acting simultaneously on a body or an object.
Mathematically, net force is given by the formula;
Where;
Fnet is the net force.
Fapp is the applied force.
Fg is the force due to gravitation.
In this scenario, a stalled car is being pushed up a hill at constant velocity by three people. Thus, the net force on the car is zero because all the forces acting on any physical object is equal to zero and represents a constant velocity; by balancing or cancelling each other out.
According to Sir Isaac Newton's First Law of Motion which is known as Law of Inertia, it states that an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.
The amount of heat needed to raise the temperature of a substance by

is given by

where
m is the mass of the substance
Cs is its specific heat capacity

is the increase in temperature
For oxygen, the specific heat capacity is approximately

The variation of temperature for the sample in our problem is

while the mass is m=150 g, so the amount of heat needed is