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Oduvanchick [21]
3 years ago
9

A figure skater begins spinning counterclockwise at an angular speed of 3.2 π rad/s. During a 4.2 s interval, she slowly pulls h

er arms
inward and finally spins at 8.8 π rad/s.
What is her average angular acceleration
during this time interval?
Answer in units of rad/s^2
Physics
1 answer:
Paha777 [63]3 years ago
3 0

Answer:

4.2 rad/s²

Explanation:

Given:

ω₀ = 3.2π rad/s

ω = 8.8π rad/s

t = 4.2 s

Find: α

ω = αt + ω₀

8.8π rad/s = α (4.2 s) + 3.2π rad/s

α = 4.2 rad/s²

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Assume that a lightning bolt can be modeled as a long, straight line of current. If 16 C of charge passes by a point in 1.50 x 1
Reptile [31]

Answer:

B = 7.9012*10^{-5}T

Explanation:

To solve the problem, the concepts related to the magnetic field and the current produced in a lightning bolt are necessary.

The current is defined by the load due to time, that is to say

I= \frac{q}{t}

Where,

q= Charge

t = time

So the current can be expressed as:

I = \frac{16}{1.5*10^{-3}}

I = 10666.67A

Once the current is found it is now possible to find the magnetic field, as this is given by the equation,

B =\frac{\mu_0}{2\pi}\frac{I}{r}

Where,

\mu_0 =Permeability Constant

I= Current

r= radius

Replacing the values we have

B=\frac{4\pi*10^{-7}}{2\pi}(\frac{10666.67}{27})

B = 7.9012*10^{-5}T

7 0
3 years ago
A baby carriage is rolling down a hill. Take into consideration, the carriage has 90J of kinetic energy and the mass of the carr
Sphinxa [80]

Answer:

YES. 6√10

Explanation:

apply E=1/2mv^2 and find the velocity of carriage which is 6√10 ms-1

as our velocity is higher than that of cart. we can catch the carriage

7 0
3 years ago
A vehicle travelling at an initial velocity of 20km/hr,accelerates at 4m/s².calculate its final velocity after 10 seconds.​
Nikitich [7]

acceleration = Velocity changes ÷ time of the velocity changes

4 m/s^2 =

4 × 10^(-3) × 3600 km / h =

4 × 3.6 =

14.4 km / h

Thus :

14.4 = V(2) - V(1) / t(2) - t(1)

14.4 = V(2) - 20 / 10

Multiply both sides by 10

10 × 14.4 = 10 × ( V(2) - 20 ) / 10

144 = V(2) - 20

Add both sides 20

144 + 20 = V(2) - 20 + 20

V(2) = 164 Km/h

Thus the final velocity after 10 seconds is 164 Km/h .

4 0
3 years ago
) Un círculo de 120 cm de radio gira a 600 rpm. Calcula: a) su velocidad angular
DIA [1.3K]

Responder:

20πrads ^ -1; 24πrads ^ -1; 0,1 seg; 10 Hz

Explicación:

Dado lo siguiente:

Radio (r) del círculo = 120 cm

600 revoluciones por minuto en radianes por segundo

(600 / min) * (2π rad / 1 rev) * (1min / 60seg)

(1200πrad / 60sec) = 20π rad ^ -1

Velocidad angular (w) = 20πrads ^ -1

Velocidad lineal = radio (r) * velocidad angular (w)

Velocidad lineal = (120/100) * 20πrad

Velocidad lineal = 1.2 * 20πrads ^ -1 = 24πrads ^ -1

C.) Período (T):

T = 2π / w = 2π / 20π = 0.1 seg

D.) Frecuencia (f):

f = 1 / T = 1 / 0.1

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5 0
3 years ago
2. A portion of the body receives 0.15 mGy from radiation with a quality factor Q = 6 and 0.22 mGy from radiation with Q = 10. (
DiKsa [7]

Answer with Explanation:

We are given that

D_1=0.15mGy

D_2=0.22mGy

Q_1=6

Q_2=10

a.We have to find the total dose

Total dose=D=D_1+D_2

Using the formula then, we get

D=0.15+0.22

D=0.37mGy

b.We have to find the total dose equivalent

Total dose equivalent=H=D_1Q_1+D_2Q_2

Using the formula

H=0.15(6)+0.22(10)

H=3.1mSv

7 0
3 years ago
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