Answer:
800 N
Explanation:
By Newton's third law which states that for every action, there is an equal and opposite reaction.
So, as the earth attracts the person towards its center, the person attracts the earth towards itself with the same magnitude of force but in the opposite direction.
Since the person is attracted towards the center of the earth by an 800 N gravitational force, the the earth is attracted toward the person with an 800 N reaction force.
Answer: The five major fields of environmental science are social sciences, geosciences, environmental chemistry, ecology, and atmospheric sciences.
Explanation:
Answer:
t=1.623 sec
Explanation:
The distance traveled before the echo is had is:

Given the speed of sound as v=345m/s, we use the speed equation to solve for t:

Hence, it takes 1.623 seconds to hear the echo.
Answer:
a) 
b) 
c) 
d) Displacement = 22 m
e) Average speed = 11 m/s
Explanation:
a)
Notice that the acceleration is the derivative of the velocity function, which in this case, being a straight line is constant everywhere, and which can be calculated as:

Therefore, acceleration is 
b) the functional expression for this line of slope 4 that passes through a y-intercept at (0, 3) is given by:

c) Since we know the general formula for the velocity, now we can estimate it at any value for 't", for example for the requested t = 1 second:

d) The displacement between times t = 1 sec, and t = 3 seconds is given by the area under the velocity curve between these two time values. Since we have a simple trapezoid, we can calculate it directly using geometry and evaluating V(3) (we already know V(1)):
Displacement = 
e) Recall that the average of a function between two values is the integral (area under the curve) divided by the length of the interval:
Average velocity = 