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Svetradugi [14.3K]
4 years ago
14

Upon impact, bicycle helmets compress, thus lowering the potentially dangerous acceleration experienced by the head. A new kind

of helmet uses an airbag that deploys from a pouch worn around the rider's neck. In tests, a headform wearing the inflated airbag is dropped from rest onto a rigid platform; the speed just before impact is 6.00 m/s. Upon impact, the bag compresses its full 12.0 thickness, slowing the headform to rest.
Required:
Determine the acceleration of the head during this event, assuming it moves the entire 12.0 cm.
Physics
1 answer:
Dimas [21]4 years ago
6 0

Answer:

acceleration = -15.3g

Explanation:

given data

speed = 6.00 m/s.

thickness = 12

moves the entire = 12.0 cm

solution

we will use here equation that is

v² - u²  = 2 × a × s    ........................1

here v = 0 is the final velocity and u = 6.0 m/s is initial velocity and s= 0.12 m is the distance covered and a is the acceleration

so we put here value and get acceleration

a = \frac{v^2-u^2}{2s}

a = \frac{0^2-6^2}{2\times 0.12}

a = -150 m/s² ( negative sign means it is a deceleration )

and

acceleration in units of g  

a = \frac{-150}{9.8}

a = -15.3 g

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3:00 - 3:02 and 3:07 - 3:08

Explanation:

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An RC circuit consists of a resistor with resistance 1.0 kΩ, a 120-V battery, and two capacitors, C1 and C2, with capacitances o
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Answer:

Q_t= 8.3 * 10^3 C

Explanation:

From the question we are told that:

Resistor R=1000ohms

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Capacitance of c_1 c_1=20 \mu F

Capacitance of c_2 c_2=60 \mu F

Time t=0

Generally the equation for charges is mathematically given by

For C_1\\Charge\ on\ C_1 = CV = 20*120 = 2400 μC = 2.4 x 10^-3 C\\Charge\ on\ C_1 = 2400 μC = 2.4 x 10^-3 C\\Charge\ on\ C_1 = 2.4 x 10^-3 C\\

ForC_2\\Charge on C_2 = 60*120 =7200 μC =  7.2 x 10^-3\\Charge on C_2 =  7.2 x 10^-3

Generally the equation for voltage across capacitors is mathematically given by

V_c(t)=V(1-e^{-t/RC})

C=C_1+C_2=80 \mu f\\t=2RC=>160000s

V_c(t)=120(1-e^{-(160000)/1000*(80)})

V_c(t)=103.7598

Generally the equation for charges is mathematically given by

Q1(t) = C1Vc(t)\\Q1(t) = 20*103.7598\\Q1(t) = 2075.196\\\\Q2(t) = 60*103.7598\\Q2(t) = 6225.6\\

Generally the equation for total charges Q_t is mathematically given by

Q_t=Q1(t)+Q2(t)

Q_t= 8.3 * 10^3 C

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3 years ago
A 75.0-kg person is riding in a car moving at 20.0 m/s when the car runs into a bridge abutment. (a) calculate the average force
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First of all, we need to calculate the acceleration of the person, by using the following SUVAT equation:

v^2 -u ^2 = 2ad

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u = 20.0 m/s is the initial velocity

a is the acceleration

d = 1.00 cm = 0.01 m is the displacement of the person

Solving for a,

a=\frac{v^2-u^2}{2d}=\frac{0-20.0^2}{2(0.01)}=-20000 m/s^2

And the average force on the person is given by

F=ma

with m = 75.0 kg being the mass of the person. Substituting,

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b) -1.0\cdot 10^5 N

In this case,

v = 0 is the final velocity

u = 20.0 m/s is the initial velocity

a is the acceleration

d  = 15.00 cm = 0.15 m is the displacement of the person with the air bag

So the acceleration is

a=\frac{v^2-u^2}{2d}=\frac{0-20.0^2}{2(0.15)}=-1333 m/s^2

So the average force on the person is

F=ma=(75)(-1333)=-1.0\cdot 10^5 N

7 0
4 years ago
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4 years ago
A parallel-plate vacuum capacitor has 7.72 J of energy stored in it. The separation between the plates is 3.30 mm. If the separa
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Final energy = Uf = initial energy *d2/d1

Final energy = Uf =7.72*1.45/3.30

(A) Final energy = Uf = 3.340J

4 0
3 years ago
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