All categories

3 years ago

(b) The figure below shows a model train, travelling at speed , approaching a

Physics

1 answer:

Andrew [12]3 years ago

3 0

Answer:

0.62 m/s

Explanation:

Given that a model train, travelling at speed , approaching a buffer model train buffer spring

The train, of mass 2.5 kg, is stopped by compressing a spring in the buffer.

After the train has stopped, the energy stored in the spring is 0.48 J.

Calculate the initial speed v of the train

Solution

The total energy stored in the spring will be equal to the kinetic energy of the train.

That is,

1/2fe = 1/2mv^2

Substitutes the spring energy, and mass into the formula

0.48 = 1/2 × 2.5 × V^2

2.5V^2 = 0.96

V^2 = 0.96 / 2.5

V^2 = 0.384

V = sqrt ( 0.384 )

V = 0.62 m/s

Therefore, the initial velocity of the train is 0.62 metres per second.

You might be interested in

A portion of the atmosphere that becomes warmer than surrounding air will ____.

earnstyle [38]

<span>A portion of the atmosphere that becomes warmer than surrounding air will expand and rise. The warmer atmosphere the more space between the molecules. Therefore, warmer atmosphere </span><span>expands to allow more space for the molecules. Cool air on the other hand, contracts because the molecules in cool air need less space.</span>

3 0

3 years ago

Two parallel plates are a distance apart with a potential difference between them. A point charge moves from the negatively char

IgorC [24]

Answer:

K' = 1200 J

Explanation:

To find the kinetic energy you first take into account the formula for the kinetic energy of the charge:

$K=\frac{1}{2}mv^2$ = 800J (1)

m: mass of the charge

v: final speed of the charge when it reaches the positively charged plate.

Furthermore, you have that the acceleration of the charge is obtained by using the second Newton law:

$F=ma=qE\\\\a=\frac{qE}{m}$ (2)

a: acceleration

E: electric field

q: charge

The electric field between two parallel plates is V/d, being V the potential difference and d the separation between plates. You replace E in (2) and obtain:

$a=\frac{qV}{md}$

Next, you take into account the following formula for the calculation of the final speed of the charge:

$v^2=v_o^2+2ad\\\\v_o=0m/s\\\\v=\sqrt{\frac{2qVd}{md}}=\sqrt{\frac{2qV}{m}}$

Next, you replace this value of v in (1):

$K=\frac{1}{2}mv^2=\frac{1}{2}m(\frac{2qV}{m})=qV$ = 880J (3)

If the distance between plates is tripled, and the potential difference is halved, you have for the new final speed:

$v'^2=v'_o^2+2a(3d)\\\\v_o=0m/s\\\\v'=\sqrt{6ad}=\sqrt{6(\frac{q}{md})\frac{V}{2}d}=\sqrt{\frac{3qV}{m}}$

And the kinetic energy becomes:

$K'=\frac{1}{2}mv^2=\frac{1}{2}m(\frac{3qV}{m})=\frac{3}{2}qV$ (4)

You calculate the ratio between both kinetic energies K and K', that is, you divide equations (3) and (4), in order to find the new kinetic energy:

$K=qV=800J\\\\K'=\frac{3}{2}qV\\\\\frac{K}{K'}=\frac{qV}{3/2\ qV}=\frac{2}{3}\\\\K'=\frac{3}{2}K=\frac{3}{2}(800J)=1200J$

hence, the kinetic energy of the charge incresases to 1200J

4 0

3 years ago

A receiver catches a football on the 50.0 yard line and is tackled 5.42 seconds later on the 12 yard line. What

tester [92]

Answer:

7.01yard/sec

Explanation:

Given parameters:

Initial position = 50yard

Final position = 12yard

Time = 5.42s

Unknown:

Average speed of runner = ?

Solution:

To solve this problem;

Speed = $\frac{distance}{time}$

Distance covered = Initial position - final position = 50 - 12 = 38yards

So;

Speed = $\frac{38}{5.42}$ = 7.01yard/sec

5 0

3 years ago

Which answer shows a balanced nuclear equation for the alpha decay of plutonium-239

Sergio [31]

Answer: An alpha particle is a helium-4 nucleus, it contains gwo protons and two neutrons. So, alpha decay, giving off an alpha particle, does the following:

1)reduces the atomic number (number of just protons) by two. Plutonium has atomic number of 94, take two protons away and you are left with 92 which corresponds to uranium.

2) reduces the mass number (protons plus neutrons) by 4. If you start with 239 and subtract two protons and two neutrons, you are left with 235.

Explanation:

7 0

3 years ago

¿Por qué el origen de ciertos metales se relaciona con la dinámica terrestre?

Lemur [1.5K]

Yo no hablo espanol

5 0

2 years ago