26.2/3.4 would be the average velocity for the run.
7.7 miles/hr
Answer:
The shortest braking distance is 35.8 m
Explanation:
To solve this problem we must use Newton's second law applied to the boxes, on the vertical axis we have the norm up and the weight vertically down
On the horizontal axis we fear the force of friction (fr) that opposes the movement and acceleration of the train, write the equation for each axis
Y axis
N- W = 0
N = W = mg
X axis
-Fr = m a
-μ N = m a
-μ mg = ma
a = μ g
a = - 0.32 9.8
a = - 3.14 m/s²
We calculate the distance using the kinematics equations
Vf² = Vo² + 2 a x
x = (Vf² - Vo²) / 2 a
When the train stops the speed is zero (Vf = 0)
Vo = 54 km/h (1000m/1km) (1 h/3600s)= 15 m/s
x = ( 0 - 15²) / 2 (-3.14)
x= 35.8 m
The shortest braking distance is 35.8 m
Answer
given,
diameter,d₁ = 7.5 cm
d₂ = 4.5 cm
P₁ = 32 kPa
P₂ = 25 kPa
Assuming, we have calculation of flow in the pipe
using continuity equation
A₁ v₁ = A₂ v₂
π r₁² v₁ = π r₂² v₂
Applying Bernoulli's equation
v₂ = 4.01 m/s
fluid flow rate
Q = A₂ V₂
Q = π (0.0225)² x 4.01
Q = 6.38 x 10⁻³ m³/s
flow in the pipe is equal to 6.38 x 10⁻³ m³/s
<h2>Right answer: Comets have very elliptical orbits that usually take them far beyond the orbit of Pluto, but also take them closer to the Sun than Earth</h2>
Comets are celestial bodies constituted by ice, dust and rocks that orbit around the Sun, after having been altered by the Oort cloud; following different trajectories that can be <u>highly eccentric elliptical</u><u> </u>(periodic trajectories), parabolic or hyperbolic.
One of the main characteristics of a comet is that it travels quite fast, on its way around the Sun and has a long tail. It should be noted that the tails of comets always go in the opposite direction to the Sun (due to the radiation pressure of sunlight).
Therefore, the correct option is C.
