<span>3.92 m/s^2
Assuming that the local gravitational acceleration is 9.8 m/s^2, then the maximum acceleration that the truck can have is the coefficient of static friction multiplied by the local gravitational acceleration, so
0.4 * 9.8 m/s^2 = 3.92 m/s^2
If you want the more complicated answer, the normal force that the crate exerts is it's mass times the local gravitational acceleration, so
20.0 kg * 9.8 m/s^2 = 196 kg*m/s^2 = 196 N
Multiply by the coefficient of static friction, giving
196 N * 0.4 = 78.4 N
So we need to apply 78.4 N of force to start the crate moving. Let's divide by the crate's mass
78.4 N / 20.0 kg
= 78.4 kg*m/s^2 / 20.0 kg
= 3.92 m/s^2
And you get the same result.</span>
Answer:
42.6 m
Explanation:
mass of crate m = 53 kg
coefficient of kinetic friction, μ = 0.36
acceleration due to gravity, g = 9.8 m/s^2
Force, F = 372.098 N
Net force, f = F - friction force
f = 372.098 - μ m x g = 372.098 - 0.36 x 53 x 9.8
f = 185.114 N
acceleration, a = f / m = 185.114 / 53 = 3.49 m/s^2
initial velocity, u = 0
time, t = 4.94 s
s = ut + 1/2 at^2
s = 0 + 1/2 x 3.49 x 4.94 x 4.94
s = 42.6 m
Answer:
Explanation:
Given
mass of box 
speed of box 
distance moved by the box 
coefficient of kinetic friction 
Friction force 


Kinetic Energy of box will be utilize to overcome friction and rest is stored in spring in the form of elastic potential energy




Answer:
The correct answer is B
Explanation:
Let's calculate the electric field using Gauss's law, which states that the electric field flow is equal to the charge faced by the dielectric permittivity
Φ
= ∫ E. dA =
/ ε₀
For this case we create a Gaussian surface that is a sphere. We can see that the two of the sphere and the field lines from the spherical shell grant in the direction whereby the scalar product is reduced to the ordinary product
∫ E dA =
/ ε₀
The area of a sphere is
A = 4π r²
E 4π r² =
/ ε₀
E = (1 /4πε₀
) q / r²
Having the solution of the problem let's analyze the points:
A ) r = 3R / 4 = 0.75 R.
In this case there is no charge inside the Gaussian surface therefore the electric field is zero
E = 0
B) r = 5R / 4 = 1.25R
In this case the entire charge is inside the Gaussian surface, the field is
E = (1 /4πε₀
) Q / (1.25R)²
E = (1 /4πε₀
) Q / R2 1 / 1.56²
E₀ = (1 /4π ε₀
) Q / R²
= Eo /1.56
²
= 0.41 Eo
C) r = 2R
All charge inside is inside the Gaussian surface
=(1 /4π ε₀
) Q 1/(2R)²
= (1 /4π ε₀
) q/R² 1/4
= Eo 1/4
= 0.25 Eo
D) False the field changes with distance
The correct answer is B
Answer:
Technique of comparing abundance ratio between radioactive isotopes to a reference isotope to determine the age of a material called radioactive dating. It determines the age by having a more abundance of isotopes in the cellular being.