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chubhunter [2.5K]

3 years ago

13

A car travels for an hour at a speed of 20 km/r, the next two hours at a speed of 65 km/r and the final hour at a speed of 85 km

/r. What is the average speed of the car for the entire trip

1 answer:

valentinak56 [21]3 years ago

6 0

Answer:

170km/hr

Explanation:

Vav=v1+v+v3.....

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an electric device is plugged into a 110v wall socket. if the device consumes 500 w of power, what is the resistance of the devi

andreev551 [17]

Answer: R=24.2Ω

Explanation: <u>Power</u> is rate of work being done in an electric circuit. It relates to voltage, current and resistance through the following formulas:

P=V.i

P=R.i²

$P=\frac{V^{2}}{R}$

The resistance of the system is:

$P=\frac{V^{2}}{R}$

$R=\frac{V^{2}}{P}$

$R=\frac{110^{2}}{500}$

R = 24.2Ω

<u>For the device, resistance is 24.2Ω.</u>

4 0

3 years ago

At a certain time a particle had a speed of 48 m/s in the positive x direction, and 4.5 s later its speed was 92 m/s in the oppo

larisa86 [58]

Answer:

$-31.1 m/s^2$

Explanation:

The acceleration of an object is the rate of change of velocity of the object.

Mathematically, it is calculated as:

$a=\frac{v-u}{t}$

where

u is the initial velocity

v is the final velocity

t is the time taken for the velocity to change from u to v

Acceleration is a vector, so it is important to also take into account the direction of the velocity.

For the particle in this problem, we have:

u = +48 m/s is the initial velocity (positive direction)

v = -92 m/s is the final velocity (negative direction)

t = 4.5 s is the time interval

Therefore, the average acceleration is

$a=\frac{v-u}{t}=\frac{-92-(+48)}{4.5}=-31.1 m/s^2$

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What causes the weight of an object to change depending on if it is on Earth or the Moon?

Gnoma [55]

The acceleration due to gravity

Brainliest please

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Atomic radius<br><br>moving from left to right across a period,<br>

Ilya [14]

Answer:

Atomic radius decreases moving from left to right across a period.

Explanation:

When we move left to right across a period, the size of atoms generally decreases. It is because within the period the outer electrons are in same valence shell and the number of electrons and proton increases moving from left to right across the the period. It increases the effective nuclear charge resulting in the increased attraction of electron to the nucleus that causes the decreased radius of the atoms.

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A series of parallel linear water wave fronts are traveling directly toward the shore at 15.5 cm/s on an otherwise placid lake.

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