Using the conservation of momentum,
ma*va1 + mb*vb1 = ma*va2 + mb*vb2
Let:
ma = mass of the ball
va = velocity of the ball
mb = mass of the man
vb = velocity of the man
The subscript 1 is known as initials while 2 is for finals.
Before the man throws the ball, he starts at rest, meaning the initial velocity of the ball and the initial velocity of the man are zero. So
0 = ma*va2 + mb*vb2
Given ma = 10 kg; va = 20 m/s; mb = 90 kg; vb is unknown, therefore
-(mb*vb2) = ma*va2
vb2 = -(ma*va2)/mb2 = -(10*20)/90 = -2.22 m/s
Notice that his velocity is negative because when he finally throws the ball (say to the right), he moves at the opposite direction (that is to the left) on which he stands on the frictionless surface.
Microwave Radiation. Microwave radiation utilizes short, high-frequency waves that penetrate food, which agitates its water molecules to create friction and transfer heat. If you're heating a solid substance, this heat energy is transferred throughout the food through conduction, while liquids do so through convection.
Answer:
(D) the sphere
Explanation:
The bodies given are Disk and Solid sphere (uniform sphere)
Moment of inertia of the bodies are
I(disk) =
I(sphere) = 
Since the moment of inertia of sphere is less than that of disk, therefore sphere will reach the bottom first.
Answer:
umm this is not a question
Explanation:
<h2>
Answer: a bee trying to escape from a closed jar </h2>
In an atom the electrons will occupy orbitals so that their energy is as small as possible. That is why the orbitals are ordered based on their energy level in an increasing order, which is associated with a particular range of energy based on its distance from the atom nucleus.
In this sense, an electron "jumps" from one level to another in the atom in the same way a bee tries to escape from a closed jar.