Response:
Once it has crossed, the locomotive requires 17.6 seconds to achieve a speed of 32 m/s.
Details:
The locomotive's acceleration is 1.6 
The duration taken to pass the crossing is 2.4 seconds.
We can apply the motion equation, v = u + at, where v represents final velocity, u indicates initial velocity, a denotes acceleration, and t signifies time.
When the speed reaches 32 m/s, we have v = 32 m/s, u = 0 m/s, and a= 1.6
.
32 = 0 + 1.6 * t
t = 20 seconds.
Therefore, the locomotive attains a speed of 32 m/s after 20 seconds, and it passes the crossing in 2.4 seconds.
Thus, after clearing the crossing, it takes an additional 17.6 seconds to reach the speed of 32 m/s.
Response:
The ball remained airborne for 3.896 seconds
Explanation:
Given that
g = 9.8 m/s², representing gravitational acceleration,
If the angle of launch is 45°, the horizontal range will be maximized.
Both horizontal and vertical launch velocities are equal, each equating to
v_h = v cos θ
v_h = 27 × cos 45°
= 19.09 m/s.
The duration to reach maximum height is half of the flight time.
v = u + at ∵ v = 0 (at maximum height)
19.09 - 9.8 t₁ = 0
t₁ = 1.948 s
The total time in the air equals twice the time to reach maximum height
2 t₁ = 3.896 s
The horizontal distance covered is
D = v × t
D = 3.896×19.09
= 74.375 m
The ball was in the air for 3.896 seconds
Answer:
a, 71.8° C, 51° C
b, 191.8° C
Explanation:
Given the data:
D(i) = 200 mm
D(o) = 400 mm
q' = 24000 W/m³
k(r) = 0.5 W/m.K
k(s) = 4 W/m.K
k(h) = 25 W/m².K
The heat generation formula can be articulated as follows:
q = πr²Lq'
q = π. 0.1². L. 24000
q = 754L W/m
Thermal conduction resistance, R(cond) = 0.0276/L
Thermal conduction resistance, R(conv) = 0.0318/L
Applying the energy balance equation,
Energy In = Energy Out
This equates to q, which is 754L
From the initial analysis, the temperature at the interface between the rod and sleeve is found to be 71.8° C
Additionally, the outer surface temperature records as 51° C
Furthermore, based on the second analysis, the calculated temperature at the center of the rod is determined to be 191.8° C
Answer:
The energy unit is expressed as kg-m/s or Joules.
Explanation:
The relationship between mass and energy in physics is represented by:

Where
m denotes the mass of the object
c signifies the speed of light
In the SI system, mass is measured in kilograms and the speed of light in m/s. Therefore, energy is defined in kg-m/s, which is equal to Joules.
Thus, the appropriate SI unit for energy is kg-m/s or Joules. This concludes the explanation.
The overall force acting on the vehicle is zero
Explanation:
Let's evaluate the situation separately for the vertical direction and the horizontal direction along the slope.
Considering the direction perpendicular to the slope, two forces are in effect:
- The weight component acting perpendicular to the slope,
, directed into the slope - The normal force N, directed outward from the slope
Equilibrium exists here, indicating the net force in this direction is zero.
Now let’s examine the parallel direction to the slope. We have two forces present:
- The weight component aligned with the slope,
, directed down the slope - The frictional force
, acting up the slope
The car moves at a constant speed in this direction, indicating that its acceleration is zero.

Thus, according to Newton's second law,

implying the net force is zero:

Learn more about slopes and friction: