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Arisa [49]
3 years ago
12

A car sitting at a red light begins to accelerate at 2.0 m/s2 when the light turns green. It continues with this acceleration un

til it reaches a speed of 20 m/s. It then travels at this speed for another few minutes. How far does the car travel in the first 46 s after the light changes to green?
Physics
1 answer:
KonstantinChe [14]3 years ago
8 0

Answer:

d = 820 m

Explanation:

here we know that car starts from rest and continue to accelerate till it will reach to maximum speed of 20 m/s

so we will have

v_f - v_i = at

20 - 0 = 2t

t = 10 s

so car will accelerate till t = 10 then it will move with uniform speed

so the distance moved by the car till it accelerates is given as

d = \frac{1}{2}at^2

d = \frac{1}{2}(2)(10^2)

d_1 = 100 m

now it will move with uniform speed for next 36 s

so we have

d_2 = 20(36) = 720 m

so total distance moved by the car is given as

d = d_1 + d_2

d = 100 + 720

d = 820 m

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Answer:

50 m/s

Explanation:

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Horizontal component of velocity = 50 m/s

A projectile motion is the motion of an object in two dimensions under the influence of gravity.

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When the projectile reaches at the maximum height it travels only along the horizontal and thus it has only horizontal velocity at that instant.

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3 years ago
If the moment acting on the cross section is M=630N⋅m, determine the maximum bending stress in the beam. Express your answer to
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Answer:

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Explanation:

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Moment of inertia from neutral axis will be given by \frac {bd^{3}}{12}+ ay^{2}

Therefore, moment of inertia will be

\frac {240\times 25^{3}}{12}+(240\times 25)\times (56.25-25/2)^{2}+2\times [\frac {20\times 150^{3}}{12}+(20\times 150)\times ((25+150/2)-56.25)^{2}]=34.5313\times 10^{6} mm^{4}}

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Bending stress at bottom=\frac {630\times 10^{3}\times 56.25}{34.5313\times 10^{6}}=1.026242858\approx 1.03 Mpa

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