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4 years ago

A 900 kg roller coaster car is travelling westward on the track and begins to slow down from 18m/s to 2m/s.

Physics

1 answer:

Anastasy [175]4 years ago

4 0

Use Newton's second law to determine the acceleration applied by the stopping force:

$F=ma\implies7024\,\mathrm N=(900\,\mathrm{kg})a\implies a\approx7.8\,\frac{\rm m}{\mathrm s^2}$

Then recall that

${v_f}^2-{v_i}^2=2a\Delta x$

Take the direction in which the car is traveling to be positive, so that its acceleration points in the opposite direction and $a$ has negative sign. Then

$\left(2\,\frac{\rm m}{\rm s}\right)^2-\left(18\,\frac{\rm m}{\rm s}\right)^2=2\left(-7.8\,\frac{\rm m}{\mathrm s^2}\right)\Delta x\implies\Delta x\approx21\,\mathrm m$

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Calculate the equivalent resistance of the circuit below.

expeople1 [14]

Answer:

30Ω

Explanation:

To calculate the equivalent resistance in the circuit, do the following:

Step 1:

10Ω and 20Ω are in series connection. Therefore their equivalent is: 10 + 20 = 30Ω

Step 2:

The equivalent resistance (30Ω) obtained from the above is in parallel connection with 30Ω resistance shown in the diagram above.

Therefore their equivalent is given by:

1/30 + 1/30 = 2/30 = 1/15.

Now invert to obtain the equivalent

Therefore, the equivalent is 15Ω

Step 3:

Determination of the overall equivalent of the resistance of the circuit.

The new equivalent resistance 15Ω obtained above is in series connection with 15Ω resistance in the diagram above.

Therefore their equivalent is given by:

15Ω + 15Ω = 30Ω

Therefore, the equivalent resistance in the circuit is 30Ω

7 0

3 years ago

A 10.0-µF capacitor is charged so that the potential difference between its plates is 10.0 V. A 5.0-µF capacitor is similarly ch

IceJOKER [234]

Answer:

Explanation:

Given that,

First Capacitor is 10 µF

C_1 = 10 µF

Potential difference is

V_1 = 10 V.

The charge on the plate is

q_1 = C_1 × V_1 = 10 × 10^-6 × 10 = 100µC

q_1 = 100 µC

A second capacitor is 5 µF

C_2 = 5 µF

Potential difference is

V_2 = 5V.

Then, the charge on the capacitor 2 is.

q_2 = C_2 × V_2

q_2 = 5µF × 5 = 25 µC

Then, the average capacitance is

q = (q_1 + q_2) / 2

q = (25 + 100) / 2

q = 62.5µC

B. The two capacitor are connected together, then the equivalent capacitance is

Ceq = C_1 + C_2.

Ceq = 10 µF + 5 µF.

Ceq = 15 µF.

The average voltage is

V = (V_1 + V_2) / 2

V = (10 + 5)/2

V = 15 / 2 = 7.5V

Energy dissipated is

U = ½Ceq•V²

U = ½ × 15 × 10^-6 × 7.5²

U = 4.22 × 10^-4 J

U = 422 × 10^-6

U = 422 µJ

6 0

4 years ago

What are the features of nanotechnology?

grigory [225]

Answer:

Characteristics of Nanotechnology

Explanation:

Nanotechnology deals with putting things together atom by atom and with structures so small they are invisible to the naked eye. It provides the ability to create materials, devices and systems with fundamentally new functions and properties

7 0

3 years ago

The velocity of a particle is given by v=20t² - 100t + 50, where v is in meters per second and t is in seconds. Evaluate the vel

allochka39001 [22]

Explanation:

It is given that,

The velocity of a particle is given by :

$v=20t^2-100t+50$

Where

v is in m/s and t is in seconds

Let a is the acceleration of the object at time t. So,

$a=\dfrac{dv}{dt}$

$a=\dfrac{d(20t^2-100t+50)}{dt}$

$a=40t-100$

When a = 0

$40t-100=0$

t = 2.5 s

a is zero at t = 2.5 s. Velocity, $v=20(2.5)^2-100(2.5)+50$

v = -75 m/s

Since, $v=\dfrac{ds}{dt}$ , s is the distance travelled

$s=\int\limits{vdt}$

$s=\int\limits{(20t^2-100t+50)dt}$

$s=\dfrac{20t^3}{3}-50t^2+50t$

At t = 2.5 s, $s=\dfrac{20(2.5)^3}{3}-50(2.5)^2+50(2.5)$

s = −83.34 m

Hence, this is the required solution.

5 0

3 years ago

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During an ultrasound, sound waves are sent by a transducer through muscle tissue at a speed of 1300 m/s. Some of the sound waves

alina1380 [7]

$2.3 \times 10^{-5} \text { seconds }$ is the time taken by the transducer to detect the reflected waves from the metal fragment after they were first emitted