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dolphi86 [110]
3 years ago
15

A car moving with an intial velocity of 60m/s is brought to rest in 30 seconds calculate the acceleration

Physics
1 answer:
gregori [183]3 years ago
6 0

Answer:

a = 2 [m/s^2]

Explanation:

To solve this problem we must use the expressions of kinematics, we must bear in mind that when a body is at rest its velocity is zero.

v_{f} = v_{i} - (a*t)

where:

Vf = final velocity = 0

Vi = initial velocity = 60 [m/s]

a = desacceleration [m/s^2]

t = time = 30 [s]

Note: the negative sign of the above equation means that the car is slowing down, i.e. its speed decreases.

0 = 60 - (a*30)

a = 2 [m/s^2]

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A balanced equation demonstrates the conservation of mass by having the same number of each type of atom on both sides of the arrow

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An electric bulb is marked 250w 230v<br>How many joule energy does it consume in 1 hour​
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I think it consumes 0.000278 energy
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Starting at its rightmost position, it takes 2 seconds for the pendulum of a grandfather clock to swing a horizontal distance of
sdas [7]

Answer:

The correct answer is b,  x = 9 cos (pi / 2 t)

Explanation:

The equation that describes a simple pendulum is

             θ  = θ₀  cos (wt + φ)

The angle is measured is radians

            θ = x / L

We replace

           d / L = x₀ / L cos (wt + φ)

            x₀ = 9 in

         

We replace

             d = 9 cos (wt + φ)

Angular velocity is related to frequency and period.

           w = 2π f = 2π / T

The period is the time of a complete oscillation T = 4 s

           w =2π / 4

           w = π / 2

Let's replace

             x = 9 cos (π/2 t + φ)

As the system is released from the root x = x₀ for t = 0 s

              x₀ = x₀ cos φ

             Cos φ = 1

             φ = 0°

The final equation is

             x = 9 cos (pi / 2 t)

The correct answer is b

8 0
3 years ago
Read 2 more answers
Racing on a flat track, a 755 kg car going 32m/s rounds a
KonstantinChe [14]

Answer:18.29m/s^2

Explanation:

Centripetal acceleration=(velocity)^2÷radius

Centripetal acceleration=(32^2)/56

Centripetal acceleration=(32×32)/56

Centripetal acceleration=1024/56

Centripetal acceleration=18.29m/s^2

5 0
4 years ago
If an object has a kinetic energy of 30 j and mass of 34kg how fast is the object moving ?
BartSMP [9]
Since the formula for kinetic energy is:

Ek = (m*V^2) / 2 where m is mass and V is speed, then we can take this equation and manipulate it a little to isolate the speed.

Ek = mv^2 / 2 — multiply both sides by 2
2Ek = mv^2 — divide both sides by m
2Ek / m = V^2 — switch sides
V^2 = 2Ek / m — plug in values
V^2 = 2*30J / 34kg
V^2 = 60J/34kg
V^2 = 1.76 m/s — sqrt of both sides
V = sqrt(1.76)
V = 1.32m/s (roughly)
4 0
3 years ago
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