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3 years ago

A train moves from rest to a speed of 30 m/s in 32.0 seconds. What is its acceleration?

Physics

1 answer:

kramer3 years ago

6 0

Answer:

0.94m/s (squared)

Explanation:

a=change in velocity/time

a=v-u/t

a=32-0=32/32

a=0.94m/s (squared)

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Power of an electric motor is 1 h.p. what does it mean ?

const2013 [10]

Answer: HP = Horse Power.

Explanation: it is the unit given to tell the motor's particular power and 1hp = 746 watts.

8 0

2 years ago

The magnitude R, measured on the Richter scale, of an earthquake of intensity I is defined as Requalslog StartFraction Upper I

lapo4ka [179]

Answer:

R = 6.8

Explanation:

Given data:

Richter scale $R = log(\frac{I}{I_o})$

where R - magnitude of earthquake of Richter scale

I - quake's intensity $= 10^{6.8} \times I_o$

$I_o$ - minimum intensity earthquake

Plugging all information in the equation to get Richter's scale

$R = log(\frac{10^{6.8} \times I_o}{I_o})$

$R = log(10^{6.8})$

R = 6.8

6 0

3 years ago

A proton, an alpha particle (a bare helium nucleus), and a singly ionized helium atom are accelerated through a potential differ

ra1l [238]

Answer:

The correct question is:

"Find the energy each gains"

The energy gained by a charged particle accelerated through a potential difference is given by

$\Delta U = q\Delta V$

where

q is the charge of the particle

$\Delta V$ is the potential difference

For a proton,

$q=+e=1.6\cdot 10^{-19}C$

And since $\Delta V=100 V$

The energy gained by the proton is

$\Delta U=(1.6\cdot 10^{-19})(100)=1.6\cdot 10^{-17}J$

For an alpha particle,

$q=+2e=3.2\cdot 10^{-19}C$

Therefore, the energy gained is

$\Delta U=(3.2\cdot 10^{-19})(100)=3.2\cdot 10^{-17}J$

Finally, for a singly ionized helium nucleus (a helium nucleus that has lost one electron)

$q=+e=1.6\cdot 10^{-19}C$

So the energy gained is the same as the proton:

$\Delta U=(1.6\cdot 10^{-19})(100)=1.6\cdot 10^{-17}J$

6 0

3 years ago

A torque of 36.5 N · m is applied to an initially motionless wheel which rotates around a fixed axis. This torque is the result

vivado [14]

Answer:

$21.6\ \text{kg m}^2$

$3.672\ \text{Nm}$

$54.66\ \text{revolutions}$

Explanation:

$\tau$ = Torque = 36.5 Nm

$\omega_i$ = Initial angular velocity = 0

$\omega_f$ = Final angular velocity = 10.3 rad/s

t = Time = 6.1 s

I = Moment of inertia

From the kinematic equations of linear motion we have

$\omega_f=\omega_i+\alpha_1 t\\\Rightarrow \alpha_1=\dfrac{\omega_f-\omega_i}{t}\\\Rightarrow \alpha_1=\dfrac{10.3-0}{6.1}\\\Rightarrow \alpha_1=1.69\ \text{rad/s}^2$

Torque is given by

$\tau=I\alpha_1\\\Rightarrow I=\dfrac{\tau}{\alpha_1}\\\Rightarrow I=\dfrac{36.5}{1.69}\\\Rightarrow I=21.6\ \text{kg m}^2$

The wheel's moment of inertia is $21.6\ \text{kg m}^2$

t = 60.6 s

$\omega_i$ = 10.3 rad/s

$\omega_f$ = 0

$\alpha_2=\dfrac{0-10.3}{60.6}\\\Rightarrow \alpha_1=-0.17\ \text{rad/s}^2$

Frictional torque is given by

$\tau_f=I\alpha_2\\\Rightarrow \tau_f=21.6\times -0.17\\\Rightarrow \tau=-3.672\ \text{Nm}$

The magnitude of the torque caused by friction is $3.672\ \text{Nm}$

Speeding up

$\theta_1=0\times t+\dfrac{1}{2}\times 1.69\times 6.1^2\\\Rightarrow \theta_1=31.44\ \text{rad}$

Slowing down

$\theta_2=10.3\times 60.6+\dfrac{1}{2}\times (-0.17)\times 60.6^2\\\Rightarrow \theta_2=312.03\ \text{rad}$

Total number of revolutions

$\theta=\theta_1+\theta_2\\\Rightarrow \theta=31.44+312.03=343.47\ \text{rad}$

$\dfrac{343.47}{2\pi}=54.66\ \text{revolutions}$

The total number of revolutions the wheel goes through is $54.66\ \text{revolutions}$ .

3 0

3 years ago

Upon examining layer M, you find that it contains a small proportion of the radioactive isotope - Potassium-40, which decays int

Westkost [7]

Answer:

t = 2.6 billion years

Explanation:

If potassium becomes 25% of its initial value

so we can say it becomes half two times

as we know that 25% means it is 1/4 times of initial value

so we will have

$N = N_o e^{-\lambda t}$

here we know that

$N = 0.25 N_o$

$0.25 = e^{-\lmabda t}$

$ln 4 = (\frac{ln 2}{T_{1/2}}) t$

$t = 2 T_{1/2}$

$t = 2(1.3 billion \: years)$

t = 2.6 billion years

4 0

3 years ago

A train moves from rest to a speed of 30 m/s in 32.0 seconds. What is its acceleration?​

A train moves from rest to a speed of 30 m/s in 32.0 seconds. What is its acceleration?