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What level of energy does electric energy belong to? What are the characteristics of alternating current?
Electric energy belongs to secondary energy. Basic knowledge of diesel generator set 1. Which six systems are included in the basic equipment of diesel generator set? Answer: (1) oil lubrication system; (2) fuel system; (3) control and protection system; (4) cooling and cooling system; (5) exhaust system; (6) starting system; 2. Why are we in
The locomotive with mass m = 500t starts from standstill with constant power. After 5min, the locomotive runs s = 2.25km on horizontal track, and the speed reaches Vmax = 15m / s
The maximum speed of the locomotive is VM = 54km / h = 15m / s. taking the locomotive as the research object, the process of the locomotive starting from standstill to reaching the maximum speed is obtained according to the kinetic energy theorem: Pt FX = 12mvm2, when the locomotive reaches the maximum speed, P = FVM = FVM. From the above two formulas, P = 3.75 × 105W, when the locomotive is moving at a constant speed, the resistance force is f = f = PVM = 2.5 × 104n, answer: (1) the power of the locomotive is 3.75 × 105W; (2) the locomotive is moving The average resistance is 2.5 × 104n
In the problem of locomotive starting, when the locomotive starts with constant power, how does the locomotive get the initial speed v?
According to the formula: P = f traction V, f traction - f resistance = ma, when the locomotive starts with constant power, the initial speed is zero, because P is not zero, so the initial speed is regarded as very small, then the traction force is very large. Therefore, it has a resultant force with the resistance, that is, the acceleration (at this time, the acceleration is the maximum). Then from the constant maximum speed, there is p = f traction v
The wheel rotation angle is proportional to the square of time. It is known that it takes 8 seconds for a wheel to rotate for one cycle. Try to find the instantaneous speed when the wheel rotates for 32 seconds
If the angle is y and the time is t, the following results are obtained
y=k*t^2
It is known that it takes 8 seconds for the wheel to rotate one cycle, i.e. t = 8, y = 2 П,
So: k = П / 32,
So y = П * T ^ 2 / 32,
v=y'=Пt/16,
So: when t = 32 seconds, v = 2 П
It is proved that the instantaneous velocity of uniform linear motion x = 3T is 3m / s by derivative. The instantaneous velocities of uniform linear motion x = 3T + T ^ 2 and x = 3T + T ^ 2 + T ^ 3 at T1 are obtained by derivative
The derivative relation between
The velocity is the derivative of the displacement,
The above words appear in the content of mathematics elective course 2-1 of senior two
But I don't quite understand the relationship between them
Use r to represent displacement, V to represent velocity, a to represent acceleration, t to represent the meaning of time... Derivative, for example, Dr / dt... There is a functional relationship between R and t... Δ R / Δ t is understood by high school students... It means that the change of displacement in a period of time is greater than that in this period of time... That is, the mean velocity... Derivative and its meaning
The displacement of an object is s = 2T + 1 / 2T ^ 2, where s is in meters and t is in seconds. The instantaneous velocity of the object at the end of 5 seconds can be calculated by using the definition of derivative
Velocity v = s' = 2 + T
So when t = 5, v = 7m / s
It is known that the instantaneous velocity is the derivative of the displacement of the moving object with respect to time, and the instantaneous acceleration is the derivative of the velocity of the moving object with respect to time,
If the equation of motion is s (T) = 1 / 3T ^ 3-3t ^ 2 + 9t, then=_ The acceleration of the object is 10
For S (T) = 1 / 3T ^ 3-3t ^ 2 + 9t, V (T) = T ^ 2-6t + 9,
Then the derivative of V (T) = T ^ 2-6t is a (T) = 2t-6
Because a = 10, then 10 = 2t-6
T = 8
The derivative particle m moves according to the rule s = 3 + 2T ^ 2, and the instantaneous velocity at t = 3 seconds is calculated
Who's going to tell me why it's 54 instead of 12
Wrong answer? 12 is right
The relationship between the displacement and time of a particle is s (T) = T & # 178; + 3 / T, and the instantaneous velocity of the particle in the second second second is obtained
s'(t)
=2t-3/t²
=2*2-3/2²
=4-3/4
=13/4 m/s
RELATED INFORMATIONS
- 1. The resistance of a locomotive in motion is constant A. If the power increases uniformly with time, the speed will increase uniformly with time. D. if the speed increases uniformly with time, the power will increase uniformly with time
- 2. Given that P is on the curve X = 2 + cos θ, y = sin θ, and point q is on the curve X = T-1, y = root 2T, try to find the minimum value of lpql, and find the coordinates of point Q at this time The root number is 2T. T is also in the root
- 3. It is proved that the function f (x) = x + 1 / X is an increasing function on [1, + infinite sign] Speed Can you have a look at my other question
- 4. What is the angle sin equals cos?
- 5. If α ∈ (π / 2, π) and sin α = 4 / 5, then the value of sin (α + π / 4) + cos (α + π) is?
- 6. If sin (π / 4 + α) = m, find the value of COS (π / 4 - α)
- 7. (sinπ/6)cosθ+sinθ(cosπ/6)=? Well, I worked out the answer of passers-by- Can you keep driving?
- 8. Given that the parabola y = a (x-1) 2 + H (a ≠ 0) intersects the X axis at two points a (x1, 0) and B (3, 0), then the length of line AB is () A. 1B. 2C. 3D. 4
- 9. The coordinates of the two intersection points of the parabola y = x square-3x-10 and X axis are
- 10. Find the vertex coordinates and axis of symmetry of the parabola y equal to the square of negative half x minus x plus three-thirds, and point out that when x takes any value, y increases with the increase of X, and when x takes any value, y decreases with the increase of X
- 11. Difference between traction power and vehicle power
- 12. Vehicle traction and power My car has a power of 188kw, a dead weight of 9 tons and a loading capacity of 6 tons. There is a hook at the rear of the car. How much weight can I drag? How to calculate? Is there a better answer
- 13. -Why is 2 sin 2T / cos t equal to - 4 sin t
- 14. Let a (2,0) be a certain point on the plane, and the graph of the moving point P (sin (2t-60 °), cos (2t-60 °) be c Let a (2,0) be a certain point on the plane, and the graph of moving point P (sin (2t-60 °), cos (2t-60 °) be c. when t changes from 30 ° to 45 °, the area of line AP sweeping graph C is calculated
- 15. Let Tan (θ / 2) = t, prove: sin θ = 2T / (1 + T ^ 2), cos θ = (1-T ^ 2) / (1 + T ^ 2), Tan θ = 2T / (11T ^ 2) Let Tan (θ / 2) = t, prove: sin θ = 2T / (1 + T ^ 2), cos θ = (1-T ^ 2) / (1 + T ^ 2), Tan θ = 2T / (1-T ^ 2)
- 16. tan(a-4π)cos(π+a)sin^2(a+3π)/tan(3t+a)cos^2(2/5π+2)=-2/1 Seeking cosa * | Tana|
- 17. F (T) = asin (ω T + φ), ω > 0, f (π / 3 + T) = f (π / 3-T), G (T) = ACOS (ω T + φ), what is g (π / 3)?
- 18. Given that the line y = x + 1 is tangent to the curve y = ln (x + a), then the value of a is______ ．
- 19. Curvature radius formula
- 20. What is the formula of curvature