Answer:
a) 
b) 
Explanation:
The complete question is written below:
An emu moving with constant acceleration covers the distance between two points that are 92 m apart in 6.5s. Its speed as it passes the second point is 14 m/s. What are (a) its speed at the first point and (b) its acceleration?
Since we are talking about constant acceleration, we can use the following equations:
(1)
(2)
Where:
is the distance between the two points
is the velocity of the emu at the first point
is the velocity of the emu at the second point
is the time it takes to the emu to cover the distance 
is the emu's constant acceleration
Knowing this, let's begin with the answers:
<h2>a) Speed at the first point</h2>
In this situation wi will use equation (1):
(1)
Finding :
(3)
(4)
(5)
<h2>
b) Emu's acceleration</h2>
Now we will substitute (5) in equation (2):
(6)
Finding :
(7) This means the emu is decreasing its speed at a constant rate.
By communication, competition and symbiosis. These are the three main ways organisms interact.
Answer:
F = 196 N
Explanation:
For this exercise we will use Newton's second law, we define a reference system with the x axis in the direction of movement of the stones and the y axis vertically
Y axis
N- W = 0
N = mg
X axis
F -fr = ma
In this case, they ask us for the force to keep moving, so the stones go at constant speed, which implies that the acceleration is zero.
F- fr = 0
F = fr
the friction force has the equation
fr = μ N
fr = μ mg
we substitute
F = μ mg
let's calculate
F = 0.80 9.8 25
F = 196 N
Alpha particles, because they are the heaviest ones (helium nuclei) and will travel around the body.
