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Lady bird [3.3K]
3 years ago
7

Simon is riding a bike at 12 km/h away from his friend Keesha.He throws a ball at 5 km/h back to Keesha, who is standing still o

n a sidewalk.
 
How fast would Keesha say the ball is traveling toward her?
Physics
1 answer:
Tems11 [23]3 years ago
5 0

I notice that even though we're working with frames of reference
here, you never said which frame the '5 km/hr' is measured in.

In fact !  You didn't even say which frame the '12 km/hr' of his
bike is measured in.

So there are several different ways this could go.  I'll do it the way
I THINK you meant it, but that doesn't guarantee anything.

-- Simon is riding his bike at 12 km/hr relative to the sidewalk,
away from Keesha.

-- He throws a ball at Keesha, at 5 km/hr relative to his own face.

-- Keesha sees the ball approaching her at (12 - 5) = 7 km/hr
relative to the ground and to her.

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kap26 [50]

Answer:

Heat

Explanation:

The term heat refers to the conduction process which occurs when energy is passed between objects

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3 years ago
Find the kinetic energy of a bullet weighing 0.10 N if its velocity is<br> 2.0 X 103 m/s?
irina1246 [14]

The kinetic energy of the bullet is 20.4 kJ.

<u>Explanation:</u>

Kinetic energy of a bullet will be equal to the product of mass of the bullet with the square of velocity or speed of the bullet and then the half of that product value.

But here the mass of the bullet is not given, instead the weight of the bullet is given in terms of force. So from this, we have to first find the mass of the bullet.

We know that as per Newton's second law of motion, force is directly proportional to the product of mass and acceleration. So here the acceleration will be equal to the acceleration due to gravity as it is weight of the object.

So F = mg

0.10 N = m × 9.8

So ,the mass of the bullet is 0.0102 kg.

Now, we know the mass and velocity of the bullet is given as 2000 m/s.

So,

kinetic energy = \frac{1}{2} × m × v²

kinetic energy = 0.5 × 0.0102 × 2000 × 2000 = 20.4 kJ

Thus, the kinetic energy of the bullet is 20.4 kJ.

5 0
3 years ago
Which two statements are true about energy transformations?
Andrej [43]
Energy is never created or destroyed. Hope this helps!
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3 years ago
What would happen if you put bubble wrap around an experiment of heat energy​
Makovka662 [10]

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3 0
3 years ago
How much magnetic potential energy is dissipated when the magnetic field is quenched in this way?
Lunna [17]

Energy is 4 * 10^{5} J

The rate of dissipation is 2 * 10^{4} W

In the question, it is given that

t = 20 s

R = 400 mm

L = 300 mm

where t, R, and L are time, radius, and length.

For magnetic energy density, the formula is

ηo = Energy / volume

     = β^2 / 2 * μ

Now, substituting the values

 = 2^{2} / 2 * 4 * Π * 10^{-7}

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Now, energy is

= energy density * volume

= 1.59 * 10^{-6} *  Π * 0.5 * 0.4^{2}

= 4 * 10^{5} J

The rate of dissipation is

= Energy / time

=  4 * 10^{5} / 20

= 2 * 10^{4} W

For more information click on the link below:

brainly.com/question/7802337

# SPJ4

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