Answer:
Sea-floor spreading occurs in the oceanic ridges. In there, volcanic activity, together with the gradual movement of the bottom, form new oceanic crust. This allows a better understanding of the continental drift explained by the theory of plate tectonics.
The greatest evidence for Sea-floor spreading is the oceanic trenches, the oceanic ridges, the magma protruding to the surface and the new seafloor.
In previous theories, continents were assumed to be transported across the sea. Harry Hess, in the 1960s, proposed the idea that the seabed itself moves as it expands from a central point. The theory is now accepted, and the phenomenon is thought to be caused by convection currents in the upper layer of the mantle.
Answer:
a) 1.22 s
b) 9.089 m
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²

Time taken by the ball to reach the highest point is 1.22 seconds

The maximum height the ball will reach above the ground is 1.75+7.339 = 9.089 m
<h3><u>Answer;</u></h3>
<em>Electric motor</em>
<h3><u>Explanation;</u></h3>
- <em><u>Energy</u></em> is the ability to do work. According to the law of conservation of energy,<em><u> energy can not be created nor destroyed but can be changed from one form to another</u></em>.
- Changing energy from one form to another is done by devices we call <em><u>transducers. These are elements that convert energy from one form to another.</u></em>
- In this case, electrical motor is an example of a transducer that converts electrical energy to kinetic energy. <em><u>Electrical energy is supplied to a the motor which converts it to rotational energy or mechanical energy then to kinetic energy.</u></em>
Answer:
The kinetic energy of the merry-goround after 3.62 s is 544J
Explanation:
Given :
Weight w = 745 N
Radius r = 1.45 m
Force = 56.3 N
To Find:
The kinetic energy of the merry-go round after 3.62 = ?
Solution:
Step 1: Finding the Mass of merry-go-round


m = 76.02 kg
Step 2: Finding the Moment of Inertia of solid cylinder
Moment of Inertia of solid cylinder I =
Substituting the values
Moment of Inertia of solid cylinder I
=>
=> 
=> 
Step 3: Finding the Torque applied T
Torque applied T =
Substituting the values
T = 
T = 81.635 N.m
Step 4: Finding the Angular acceleration
Angular acceleration ,
Substituting the values,


Step 4: Finding the Final angular velocity
Final angular velocity ,
Substituting the values,


Now KE (100% rotational) after 3.62s is:
KE = 
KE =
KE = 544J