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3 years ago

A motorist driving at 25 meters/second decelerates to

Physics

2 answers:

prisoha [69]3 years ago

6 0

Answer:

Kinetic energy = (1/2) (mass) (speed)²

Before slowing down, the car's speed is 25 m/s,

and its kinetic energy is ...

(1/2) (1,500 kg) (25 m/s)²

= (1/2) (1,500 kg) (625 m²/s²)

= 468,750 joules .

After slowing down, the car's speed is 15 m/s,

(1/2) (1,500 kg) (15 m/s)²

= (1/2) (1,500 kg) (225 m²/s²)

= 168,750 joules.

The car lost (468,750 - 168,750) = 300,000 joules

and you heard it from the KING

timama [110]3 years ago

5 0

Kinetic energy = (1/2) (mass) (speed)²

Before slowing down, the car's speed is 25 m/s,
and its kinetic energy is ...

   (1/2) (1,500 kg) (25 m/s)²

      = (1/2) (1,500 kg) (625 m²/s²)

      =    468,750 joules .

After slowing down, the car's speed is 15 m/s,
and its kinetic energy is ...

   (1/2) (1,500 kg) (15 m/s)²

      = (1/2) (1,500 kg) (225 m²/s²)

      = 168,750 joules.

The car lost (468,750 - 168,750) = 300,000 joules of K.E.

The law of Conservation of Energy says:

That 300,000 joules had to go somewhere.

If it's a standard, gas-powered car, then the kinetic energy got
put into the brakes. The energy turned into heat, and the heat
was carried off in the air.

If it's a more modern electric or hybrid car, then the kinetic energy
spun the wheel motors, turning them temporarily into electrical
generators. The generators converted the kinetic energy into
electrical energy, which got put back into the car's batteries, and
could be used again. That's why electric cars use less gas.

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Rock at the top of a 20 m tall hill the rock has a mass of 10 kg how much potential energy does it have

Blizzard [7]

PE = 10 * 10 * 20 = 2000 Joule

6 0

3 years ago

Read 2 more answers

Somebody please help me with this question..!

Rudik [331]

8.1) Here, Pressure increases with depth in the ocean at higher rate then that of increase in altitude in atmosphere. So, the rate of change of pressure is different in these journeys.So, your most correct answer would be option D.

8.2) Difference in the shape of lines is due to different density of air & water. So, that physical property and your answer would be option A

So, in Short Answers of your questions are:
8.1) - Option D
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Hope this helps!

3 0

3 years ago

Which is evidence that a convergent boundary once existed

Vladimir79 [104]

Volcanic islands, Mountain ranges

Explanation:

A convergent margin is plate boundary in which plates comes together. There are different types of interactions that occurs around a place where plate converges.

An ocean-continent convergence creates a subduction zone in which the denser oceanic plate sinks beneath the less dense continental crust.
As the oceanic plate begins to subside, it can melt and form chains of volcanic island within the riding continents.
Also, where two plates of equal densities converge, none of them subsides and this leads to upbuilding.
The product can be seen as extensive mountain ranges on earth like the Andes and Himalayas.

Learn more:

Descending lithosphere brainly.com/question/9582362

#learnwithBrainly

8 0

3 years ago

I really don’t get this one

worty [1.4K]

Compounds are molecules with 2 or more elements

So the answer would be the third one

CO2;H2O

4 0

3 years ago

An amateur player is about to throw a dart with an initial velocity of 15 meters/second onto a dartboard that is at a distance o

Minchanka [31]

Answer:

B. 0.16 m

Explanation:

The vertical distance by which the player will miss the target is equal to the vertical distance covered by the dart during its motion.

Since the dart is thrown horizontally, the initial vertical velocity is zero:

$v_y = 0$

While the horizontal velocity is

$v_x = 15 m/s$

The horizontal distance covered is

$d_x = 2.7 m$

Since the dart moves by uniform motion along the horizontal direction, the time it takes for covering this distance is

$t=\frac{d_x}{v_x}=\frac{2.7 m}{15 m/s}=0.18 s$

along the vertical direction, the motion is a uniformly accelerated motion with constant downward acceleration g=9.8 m/s^2, so the vertical distance covered is given by

$d_y = \frac{1}{2}gt^2=\frac{1}{2}(9.8 m/s^)(0.18 s)^2=0.16 m$

8 0

4 years ago