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2 years ago

If a 2 kg ball is traveling at a speed of 4 m/s, what is its kinetic energy?

Physics

2 answers:

Kay [80]2 years ago

8 0

Answer: 16J

Explanation:

K.E = $\frac{1}{2}$ m $v^{2}$

K.E = $\frac{1}{2}$ X 2 X 16

K.E = 16

Art [367]2 years ago

4 0

The kinetic energy of the ball is 16 J.

Answer: Option D

<u>Explanation: </u>

Kinetic energy is the form of energy exhibited by a body when it is in motion. The kinetic energy will be directly proportional to the mass of the body as well as to the square of the speed of the body at which it is moving. So the mathematical representation of kinetic energy of any object is

$\text {Kinetic energy}=\frac{1}{2} \times m \times(v)^{2}$

In the present case, the ball is the object with mass of around 2 kg and it is moving with the speed of about 4 m/s. So, the kinetic energy exhibited by the ball during its motion is

$\text {Kinetic energy of the ball}=\frac{1}{2} \times 2 \times(4)^{2}=16 \mathrm{J}$

So, the kinetic energy exhibited by the ball is 16 J.

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Which scenario presents a possible environmental impact due hydrogen fuel cells?

Mekhanik [1.2K]

The scenario that presents a possible environmental impact due to hydrogen fuel cells is that, the electricity used to supply the fuel cells with Hydrogen is produced using fossil fuels.

The question is incomplete, but these should have been the options;

a.) The fuel cells are used to power internal combustion engines rather than electric motors.

b.) The electricity used to supply the fuel cells with hydrogen is produced using fossil fuels.

c.) The combined exhaust emissions from fleets of buses equipped with fuel cells generates smog.

d.) None of these are correct.

The answer therefore is option B. The Hydrogen fuel cell is a device that uses Hydrogen as an energy source to power machines and to generate heat and electricity. It is a green energy alternative to fossil fuels as unlike fossil fuels, it doesn't produce green house gases and is non-toxic. Also, unlike other clean sources of energy like wind and water, it doesn't require a large area of land to be produced.

Hydrogen fuel cells work by combining hydrogen and oxygen atoms. The resulting energy produced is converted to electrical energy which can be used to power electrical motors, while the by-product, water is non-toxic, renewable and doesn't create smog.

However, to produce the hydrogen used in the cells, high amount of energy is required in order to separate hydrogen from oxygen. To accomplish this, fossil fuels such as coal, natural gas and oil are used, releasing harmful emissions which creates a negative environmental impact. This makes the answer to the above question option B. A better alternative though, is to use other renewable energy sources like wind or solar.

To learn more about the benefits of Hydrogen fuel cells, visit;

brainly.com/question/6501095

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8 0

11 months ago

A constant force of 45 N directed at angle θ to the horizontal pulls a crate of weight 100 N from one end of a room to another a

Rasek [7]

Answer:

$W=173.48J$

Explanation:

information we know:

Total force: $F=45N$

Weight: $w=100N$

distance: $4m$

vertical component of the force: $F_{y}=12N$

-------------

In this case we need the formulas to calculate the components of the force (because to calculate the work we need the horizontal component of the force).

horizontal component: $F_{x}=Fcos\theta$

vertical component: $F_{y}=Fsen\theta$

but from the given information we know that $F_{y}=12N$

so, equation these two $F_{y}=Fsen\theta$ and $F_{y}=12N$

$Fsen\theta =12N$

and we know the force $F=45N$ , thus:

$45sen\theta=12$

now we clear for $\theta$

$sen\theta =12/45\\\theta=sin^{-1}(12/45)\\\theta =15.466$

the angle to the horizontal is 15.466°, with this information we can calculate the horizontal component of the force:

$F_{x}=Fcos\theta$

$F_{x}=45cos(15.466)\\F_{x}=43.37N$

whith this horizontal component we calculate the work to move the crate a distance of 4 m:

$W=F_{x}*D\\W=(43.37N)(4m)\\W=173.48J$

the work done is W=173.48J

7 0

2 years ago

A cyclist going downhill is accelerating at 1. 2 m/s2. If the final velocity of the cyclist is 16 m/s after 10 seconds, what is

mel-nik [20]

Answer:

$\boxed {\boxed {\sf v_i= 4 \ m/s}}$

Explanation:

We are asked to find the cyclist's initial velocity. We are given the acceleration, final velocity, and time, so we will use the following kinematic equation.

$v_f= v_i + at$