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liubo4ka [24]
3 years ago
10

a dump truck travels 70mph for 3 hours, then for 20mph for another 2 hours in the same direction. what is the average speed the

car traveled?
Physics
1 answer:
Dmitry_Shevchenko [17]3 years ago
8 0

Answer:

the average speed of the car is 170 mph.

Explanation:

Given;

initial speed, u = 70 mph

time of motion, t₁ = 3 hours

final speed, v = 20 mph

time of motion, t₂ = 2 hours

The average speed of the car is calculated as;

v' = \frac{70(3) - 20(2)}{3-2} \\\\v' = 170 \ mph

Therefore, the average speed of the car is 170 mph.

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A particle in a 799=m-long linear particle accelerator is moving at 0.875C. How long does the particle accelerator appear to the
barxatty [35]

the answer is 386m because m = pi mc=2.23

6 0
2 years ago
A battery charges a parallel-plate capacitor fully and then is removed. The plates are immediately pulled apart. (With the batte
Assoli18 [71]

Answer:

<em>There will be an increase in potential difference.</em>

Explanation:

As we know that the potential difference depends upon the capacitance.

ΔV = Q/C

When battery is disconnected the charge remains constant on the plates but the capacitance decreases. As the capacitance has an inverse relation with the potential difference, there will be an increase in it.

In addition to that the potential difference can also be defined as the product of field and distance between the plates. As the charge is constant so the field is constant. Upon increasing the separation between the plates the potential difference will also increased.

4 0
3 years ago
A small truck has a mass of 2145 kg. How much work is required to decrease the speed of the vehicle from 25.0 m/s to 12.0 m/s on
MAXImum [283]

Answer:

The work required is -515,872.5 J

Explanation:

Work is defined in physics as the force that is applied to a body to move it from one point to another.

The total work W done on an object to move from one position A to another B is equal to the change in the kinetic energy of the object. That is, work is also defined as the change in the kinetic energy of an object.

Kinetic energy (Ec) depends on the mass and speed of the body. This energy is calculated by the expression:

Ec=\frac{1}{2} *m*v^{2}

where kinetic energy is measured in Joules (J), mass in kilograms (kg), and velocity in meters per second (m/s).

The work (W) of this force is equal to the difference between the final value and the initial value of the kinetic energy of the particle:

W=\frac{1}{2} *m*v2^{2}-\frac{1}{2} *m*v1^{2}

W=\frac{1}{2} *m*(v2^{2}-v1^{2})

In this case:

  • W=?
  • m= 2,145 kg
  • v2= 12 \frac{m}{s}
  • v1= 25 \frac{m}{s}

Replacing:

W=\frac{1}{2} *2145 kg*((12\frac{m}{s} )^{2}-(25\frac{m}{s} )^{2})

W= -515,872.5 J

<u><em>The work required is -515,872.5 J</em></u>

3 0
3 years ago
How much metabolic energy is required for a 68kg person to run at a speed of 15km/hr for 15min ?
irga5000 [103]
<span>What I have here is exactly the same problem, however, with the time changed to 19 mins:

metabolic energy = metabolic power*time = 1.150*19*60 = 1.311 kJ..corresponding to 1.311/4.186 = 313,2 Cal or kcal 

If we reasonably assume a metabolic eff.cy of 20%, it means we need to assume food for 1500 Cal approx.

Just plug the value t=15min to the equation and you will surely get the correct answer.

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
</span>
8 0
2 years ago
Explain how an electrical wet cell functions.
Fynjy0 [20]
The chemical reaction causes electricity to flow through the terminals to the load attached. Some of the acid in the battery remains on the plates as it flows through. When the battery is recharged the acid is returned to the liquid solution to provide more power later.
3 0
3 years ago
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