Answer:
Point A (Maximum height)
Explanation:
Potential energy is given as the product of mass, height and acceleration due to gravity hence expressed as mgh where m is the mass of roller coaster, h is the height and g is acceleration due to gravity. Since the mass and g are constant for a roller coaster, the main factor that will influence the magnitude of energy is the height. The higher the height, the higher the potential energy and vice versa. Using the attached image, the highest point is point A
Answer:
See below
Explanation:
Vertical position = 45 + 20 sin (30) t - 4.9 t^2
when it hits ground this = 0
0 = -4.9t^2 + 20 sin (30 ) t + 45
0 = -4.9t^2 + 10 t +45 = 0 solve for t =4.22 sec
max height is at t= - b/2a = 10/9.8 =1.02
use this value of 't' in the equation to calculate max height = 50.1 m
it has 4.22 - 1.02 to free fall = 3.2 seconds free fall
v = at = 9.81 * 3.2 = 31.39 m/s VERTICAL
it will <u>also</u> still have horizontal velocity = 20 cos 30 = 17.32 m/s
total velocity will be sqrt ( 31.39^2 + 17.32^2) = 35.85 m/s
Horizontal range = 20 cos 30 * t = 20 * cos 30 * 4.22 = 73.1 m
Answer;
B. Increased levels of carbon dioxide, a greenhouse gas, leads to increased phytoplankton growth.
Explanation;
-A combination of warm water, high nutrient levels, and adequate sunlight may cause a harmful algae bloom. These blooms may damage aquatic ecosystems by blocking sunlight and depleting oxygen that other organisms need to survive.
-Algae blooms have been increasing globally, and climate change may be playing a role in the increment. For instance, during the warm summer season or when water is warmer, some harmful types of algae to grow faster than other, more benign varieties.
-Additionally, the warmer surface water also prevents water from mixing vertically, allowing algae to grow thicker and faster.
Answer:5.60 m/s
Explanation:
Given
Coefficient of static friction 
Coefficient of kinetic friction 
mass of crate 
Force applied 
maximum static Friction 



thus applied force is greater than Static friction therefore kinetic friction will come into play


net Force on crate 

Magnitude of velocity can be obtained by using

where v=final velocity
u=initial velocity
a=acceleration
s=displacement
here initial velocity is zero as crate start from rest


The correct answer is
<span>b. increases with the square of speed
In fact, the kinetic energy of a moving object is given by
</span>

<span>where m is the mass of the object and v is its speed. We see that the kinetic energy is directly proportional to the square of the speed, therefore option B is the correct one.</span>