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2 years ago

6

If a vehicle is traveling at constant velocity and then comes to a sudden stop, has it undergone negative acceleration or positi

ve acceleration? Explain your answer

1 answer:

sertanlavr [38]2 years ago

6 0

Answer:

Negative acceleration

Explanation:

Let us assume a vehicle is moving with a constant velocity u and then it comes to a sudden stop.

The initial velocity of the vehicle is u and finally it comes to rest, it means final velocity is 0.

As we know that,

Acceleration is equal to change in velocity divided by time taken.

$a=\dfrac{v-u}{t}\\\\\text{Put v=0}\\\\a=\dfrac{-u}{t}$

We can see that the value of acceleration is negative. Hence, it leads to negative acceleration.

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A spring stretches 0.150 m when a 0.30 kg mass is hung from it. The spring is then stretched an additional 0.100 m from this equ

DochEvi [55]

Answer:

a) $k=19.6N/m$

b) $V_m=0.81m/s$

c) $a_m=6.561m/s^2$

d) $K.E=0.096J$

e) $T=0.78sec$ & $F=1.29sec$

f) $mx'' + kx' =0$

Explanation:

From the question we are told that:

Stretch Length $L=0.150m$

Mass $m=0.30kg$

Total stretch length $L_t=0.150+0.100=>0.25$

a)

Generally the equation for Force F on the spring is mathematically given by

$F=-km\\\\k=F/m\\\\k=\frac{m*g}{x}\\\\k=\frac{0.30*9.8}{0.15}$

$k=19.6N/m$

b)Generally the equation for Max Velocity of Mass on the spring is mathematically given by

$V_m=A\omega$

Where

A=Amplitude

$A=0.100m$

And

$\omega=angulat Velocity\\\\\omega=\sqrt{\frac{k}{m}}\\\\\omega=\sqrt{\frac{19.6}{0.3}}\\\\\omega=8.1rad/s$

Therefore

$V_m=A\omega\\\\V_m=8.1*0.1$

$V_m=0.81m/s$

c)

Generally the equation for Max Acceleration of Mass on the spring is mathematically given by

$a_m=\omega^2A$

$a_m=8.1^2*0.1$

$a_m=6.561m/s^2$

d)

Generally the equation for Total mechanical energy of Mass on the spring is mathematically given by

$K.E=\frac{1}{2}mv^2$

$K.E=\frac{1}{2}*0.3*0.8^2$

$K.E=0.096J$

e)

Generally the equation for the period T is mathematically given by

$\omega=\frac{2\pi}{T}$

$T=\frac{2*3.142}{8.1}$

$T=0.78sec$

Generally the equation for the Frequency is mathematically given by

$F=\frac{1}{T}$

$F=1.29sec$

f)

Generally the Equation of time-dependent vertical position of the mass is mathematically given by

$mx'' + kx' =0$

Where

'= signify order of differentiation

7 0

3 years ago

describe at least two ways in which parents are able to influence the drinking habits of their children

laiz [17]

Well parents can set rules or even punishments which can influence the drinking habits of there kids such as, they aren't allowed to go out unless they had followed the rule there parents set for the amount they needed to have drank. Parents have many ways in which there authority can influence there kids habits.

6 0

3 years ago

Read 2 more answers

A 1150 kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 7.69 m before contacting the beam,

Natasha_Volkova [10]

Answer:

the average force 11226 N

Explanation:

Let's analyze the problem we are asked for the average force, during the crash, we can find this from the impulse-momentum equation, but this equation needs the speeds and times of the crash that we could look for by kinematics.

Let's start looking for the stack speeds, it has a free fall, from rest (Vo=0)

Vf² = Vo² - 2gY

Vf² = 0 - 2 9.8 7.69 = 150.7

Vf = 12.3 m / s

This is the speed that the battery likes when it touches the beam. They also give us the distance it travels before stopping, let's calculate the time

Vf = Vo - g t

0 = Vo - g t

t = Vo / g

t = 12.3 / 9.8

t = 1.26 s

This is the time to stop

Now let's use the equation that relates the impulse to the amount of movement

I = Δp

F t = pf-po

The amount of final movement is zero because the system stops

F = - po / t

F = - mv / t

F = - 1150 12.3 / 1.26

F = -11226 N

This is the average force exerted by the stack on the vean

7 0

3 years ago

Which of the following statements are true about the international system of measurement?

anygoal [31]

The International System Units or the SI units is scientific method of expressing the magnitudes or quantities of important natural phenomena. There are seven base units in the system, from which other units are derived. This system was formerly called the meter-kilogram-second (MKS) system.

8 0

3 years ago

A ball rolls down the hill which has a vertical height of 15 m. Ignoring friction what would be the gravitational potential ener

trasher [3.6K]

a) Potential energy: 147 m [J]

The gravitational potential energy of an object is given by

$U=mgh$

where

m is its mass

$g=9.8 m/s^2$ is the acceleration of gravity

h is the height of the object above the ground

In this problem,

h = 15 m

We call 'm' the mass of the ball, since we don't know it

So, the potential energy of the ball at the top of the hill is

$U=(m)(9.8)(15)=147 m$ (J)

b) Velocity of the ball at the bottom of the hill: 17.1 m/s

According to the law of conservation of energy, in absence of friction all the potential energy of the ball is converted into kinetic energy as the ball reaches the bottom of the hill. Therefore we can write:

$U=K=\frac{1}{2}mv^2$

where

v is the final velocity of the ball

We know from part a) that

U = 147 m

Substituting into the equation above,

$147 m = \frac{1}{2}mv^2$

And re-arranging for v, we find the velocity:

$v=\sqrt{2\cdot 147}=17.1 m/s$

5 0

3 years ago