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
Hi there!
We can use Newton's Second Law:

∑F = net force (N)
m = mass (kg)
a = acceleration (m/s²)
We are given the mass and acceleration, so:
∑F = 20 · 2 = <u>40 N</u>
Greetings!
The correct answer choice is Choice 4.
<em>Why?</em>
In a scientific experiment the only thing being changed is the independent variable. Everything else should stay the same.
In this experiment, the independent variable is the amount of sunlight each plant should receive. <em>Here's a tip</em>- when looking for and independent variable look for whats being changed on purpose.
Hope this helps!
~Fluerie
Answer:
1.57772 m
Explanation:
M = Mass of actor = 84.5 kg
m = Mass of costar = 55 kg
v = Velocity of costar
V = Velocity of actor
= Intial height of actor = 4.3 m
g = Acceleration due to gravity = 9.81 m/s²
As the energy of the system is conserved

As the linear momentum is conserved

Applying conservation of energy again

The maximum height they reach is 1.57772 m
8500 Hz and Longitudinal
Speed = frequency x wavelength
Speed of sound at 20 degrees Celsius is approximately 340 m/s