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.
Answer:
An electric fan is considered to be a mixture of several simple machines. It includes the Wheel and Axle type, wedges, and the Inclined plane types. The blades of an electric fan are the inclined planes and the wedges.
The variable that changes is the period of the motion.
<h3>What is simple harmonic motion?</h3>
The term simple harmonic motion refers to a regular repeating motion. The acceleration of the SHM is always directed towards the center. The spring is an example of a system undergoing simple harmonic motion.
From the description in the question, the variable that changes is the period of the motion.
Learn more about simple harmonic motion: brainly.com/question/17315536
The match making one is Radiation is i think B and Convection i think is C and Conduction i think is A. I think 1 is radiation. Because radiation is transferred between objects or an empty space. Number 2 i think is conduction Because conduction is the transfer of thermal energy between to objects touching. Number 3 i also i think is radiation because radiation transfers between objects. Number 4 i also think is conduction because the spoon was touching a hot pot that was on the stove so then the thermal energy was transferred between the two objects touching. number 5 I think is convection because convection is the transfer of energy by the movement of a fluid, such as air or water. Number 6 i think is radiation because the snake is not touching the lamp and radiation goes all across spaces. Number 7 i think is convection because convection is the movement of a fluid, such as air or water. Hope this helps sorry its so long :)
