Definite integral in physics


1.A particle moves in a straight line with acceleration a = 2.6 m.s-2. Determine the velocity equation and the displacement equation (if v0 = 0, s0 = 0). Calculate the velocity and displacement at time t = 2s.

Solution:

definite-integral-in-physics-1


2.Determine the work required to stretch a spring by 25 cm from its unstretched state, given that a force of 16 N, parallel to the spring’s axis, stretches it by 80 cm.

Solution:

F = 16 N, x = 80 cm = 0.8 m, a = 0, b = 25 cm = 0.25 m.

The force F is directly proportional to the extension x

definite-integral-in-physics-2


3.Determine the effective value of an alternating sinusoidal current

definite-integral-in-physics-3q

Solution:

definite-integral-in-physics-3a


4.An alternating electric current with maximum value Imax flows through a stove coil with resistance R. Derive the formula for calculating the amount of Joule heat. The instantaneous current is: i = Imaxsin ωt.

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5.What distance is traveled by a body moving with velocity v =  At2 + Bt + C during the first 10 seconds of motion, if:

  • A = 3ms-1
  • B = 1ms-1
  • C = –1ms-1
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6.Calculate the distance traveled by a raindrop in the first 6 seconds. Neglect air resistance.

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7. What work must be done for a body of mass m to increase its speed from v1 to v2?

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8.What work is done by an external force when stretching a steel rod of length l0 = 2m and cross-sectional area
S = 5mm2 by 1 mm with elastic deformation?

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9.Calculate the work required to lift a body of mass m to a height h above the Earth’s surface. Use the relation:

definite-integral-in-physics-9q
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10. How long will it take for water, poured into a cylindrical vessel with base area S = 420cm2 and water height h = 40cm, to flow out through an opening at the bottom. The opening has area s = 2cm2. The outflow velocity is given by:

  • v = μ.s.(2.g.x)1/2
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11.Calculate the coordinates of the centroid of a square with side a = 6 cm.

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12.Calculate the coordinates of the centroid of the plane figure bounded by the function:

  • f(x) = y = x3, for  x ∈ <0 ,1>
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13. Calculate the coordinates of the centroid of the plane figure bounded by:

  • the parabola y = x2
  • and the lines y = 0,  x = 1.
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14.Determine the coordinates of triangle ΔABO formed by

  • the line y = –x + 6 in the coordinate system. A[6 , 0],  B[0 ,6],  O[0, 0]
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15. Find the coordinates of the centroid of the plane figure bounded by the curve:

  • a2y = bx2 for x ∈ < 0 ; a >
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