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3 years ago

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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3 years ago

State Schrodinger equation.

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2 years ago

Help me please I can't get the final step

inna [77]

Answer:

$\displaystyle m=\frac{2}{3},\ n=\frac{4}{3}$

Explanation:

Dimensional Analysis

It's given the relation between quantities A, B, and C as follows:

$\displaystyle A=\frac{3}{2}B^mC^n$

and the dimensions of each variable is:

$A=L^2T^2$

$B=LT^{-1}$

$C=LT^2$

Substituting the dimensions into the relation (the coefficient is not important in dimension analysis):

$\displaystyle L^2T^2=\left(LT^{-1}\right)^m\left(LT^2\right)^n$

Operating:

$L^2T^2=\left(L^mT^{-m}\right)\left(L^nT^{2n}\right)$

$L^2T^2=L^{m+m}T^{-m+2n}$

Equating the exponents:

$m+n=2$

$-m+2n=2$

Adding both equations:

$3n=4$

Solving:

$n=4/3$

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Answer:

$\mathbf{\displaystyle m=\frac{2}{3},\ n=\frac{4}{3}}$

6 0

3 years ago

a car with a mass of 2000 kilograms is moving around a circular curve at a uniform velocity of 25 meters per second. The curve h

melisa1 [442]

In the given problem, we say various information's that are going to help us reach the ultimate answer to the question. Let us first write the information's that have been presented in front of us.
Mass of the car = 2000 kg
Velocity of the car = 25 m/s^2
Radius of the circle = 80 m
Now we already know the equation for calculating the centripetal force and that is
Centripetal Force = [mass * (velocity)^2]/Radius
      = [2000 * (25)^2]/80
      = (2000 * 625)/80
      = 1250000/80
      = 15625
So the centripetal force on the car is 15625 Newtons

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3 years ago

Read 2 more answers

A spinning wheel is slowed down by a brake, giving it a constant angular acceleration of ?5.20 rad/s2. during a 3.80-s time inte

ddd [48]

We can answer this using the rotational version of the kinematic equations:
θ = θ₀ + ω₀t + ½αt² -----> 1

ω² = ω₀² + 2αθ -----> 2

Where:

θ = final angular displacement = 70.4 rad

θ₀ = initial angular displacement = 0

ω₀ = initial angular speed

ω = final angular speed

t = time = 3.80 s

α = angular acceleration = -5.20 rad/s^2

Substituting the values into equation 1:
70.4 = 0 + ω₀(3.80) + ½(-5.20)(3.80)² 

ω₀ = (70.4 + 37.544) / 3.80 

ω₀ = 28.406 rad/s 

Using equation 2:
ω² = (28.406)² + 2(-5.2)70.4

ω = 8.65 rad/s

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3 years ago