The kinematics and Newton's second law we can find the results for the questions about the braking movement of the car are;
Question 1.
a) The stopping distance is: x = 270 m
b) The initial velocity is: v₀ = 17.3 m / s
c) Concepts of kinematics and Newton's second law show us the expressions to make safe trips and avoid accidents on the roads.
Question 2.
- The stopping distance is: x = 4d
Given parameters
- Mass of the red carriage m1 = 2,0 10³ kg
- Red car speed vo = 45 m / s
- Friction force fr = 7.5 10³ N.
To find
Question 1.
a) Minimum braking distance.
b) If the distance is x = 40.0 m, what speed should the vehicles have?
c) Conclusive importance of physics in daily life.
Question 2.
Kinematics studies the movement of bodies, looking for relationships between the position, speed and acceleration of bodies.
v² = v₀² - a2 x
Where v and v₀ are the current and initial velocity, respectively, at acceleration and x the distance traveled.
Newton's second law states that the net force is proportional to the mass and the acceleration of the body.
F = ma
Where F is force, m is mass and acceleration.
In the attachment we see a diagram of the forces in the system. Let's look for the acceleration of the body
fr = m a
a =[tex]\frac{fr}{m}[/tex]
a = [tex]\frac{7.5 \ 10^3}{2.0 \ 10^3 }[/tex]
a = 3.75 m / s²
This acceleration is in the opposite direction to the speed.
Let's find the distance needed to stop, the final speed is zero.
0 = v₀² - 2 ax
x = [tex]\frac{v_o^2 }{ 2a}[/tex]
Let's calculate.
x = [tex]\frac{45^2 }{2 3.75}[/tex]
x = 270 m
This is the minimum distance that the two vehicles must separate to avoid a collision.
b) We look for speed.
v₀ = [tex]\sqrt{2ax}[/tex]
v₀ = [tex]\sqrt{2 \ 3.75 \ 40.0}[/tex]
v₀ = 17.3 m / s
c) The concepts of kinematics and Newton's second law show us the expressions to make safe trips and avoid accidents on the roads.
2) They indicate that the initial velocity is v and the distance traveled to stop is d, let's find the acceleration.
0 = v₀² - 2ax
Let's substitute.
a = [tex]\frac{v^2}{2d}[/tex]
They ask the distance traveled if this car traveled from an initial speed 2v.
0 = v² - 2 a x
x = [tex]\frac{v^2}{2a}[/tex]
We substitute
x = [tex]\frac{(2v)^2 }{2} \ (\frac{2d}{v^2})[/tex]
x = 4 d
In conclusion, using the kinematic relations and Newton's second law we can find the results for the questions about the braking movement of the car are;
Question 1
a) The stopping distance is: x = 270 m
b) The initial velocity is: v₀ = 17.3 m / s
c) concepts of kinematics and Newton's second law show us the expressions to make safe trips and avoid accidents on the roads.
Question 2.
- The stopping distance is x = 4d
Learn more about kinematics here: brainly.com/question/13202578
