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4 years ago

Which statement correctly describes one of the changes?

Physics

2 answers:

Dima020 [189]4 years ago

8 0

It'd be A. Picture one shows a chemical change. Rust is made from the iron reacting with oxygen.

user100 [1]4 years ago

6 0

Answer: Option (A) is the correct answer.

Explanation:

A chemical change is defined as the change which leads to change in chemical composition of a substance.

During a chemical change there occurs formation of a new substance.

For example, in picture 1 when pipes are exposed to air for a few months then color of all the pipes changed. This shows that oxidation has taken place that is, it is a chemical change.

On the other hand, in picture 2 liquid state of water changes into solid state that is, formation of ice takes place. As state of matter is changing and no formation of any new substance occurs so it is a physical change.

Thus, we can conclude that the statement picture I shows a chemical change, because a new substance is formed, correctly describes one of the changes.

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In the figure, a proton is projected horizontally midway between two parallel plates that are separated by 0.50 cm, and are 5.60

noname [10]

a) Minimum speed of the proton: $6.05\cdot 10^6 m/s$

b) Angle of the velocity: $\theta=-5.1^{\circ}$

Explanation:

The proton experiences a vertical force due to the electric field, given by:

$F=qE$

where

$q=1.6\cdot 10^{-19}C$ is the proton charge

$E=610,000 N/C$ is the magnitude of the electric field

The vertical acceleration of the proton is therefore

$a=\frac{qE}{m}$

where

$m=1.67\cdot 10^{-27}kg$ is its mass

Therefore, the vertical position of the proton at time t is

$y(t)=\frac{1}{2}at^2=\frac{1}{2}\frac{qE}{m}t^2$

where we assumed that the initial vertical velocity is zero (because the proton is fired horizontally) and the initial vertical position, halfway between the two plates, is the origin.

The horizontal motion of the proton instead is uniform, so the horizontal position is given by

$x(t)=v_0 t$

where $v_0$ is the initial speed. This equation can be rewritten as

$t=\frac{x(t)}{v_0}$

And substituting into the eq. for y,

$y(t) = \frac{1}{2}\frac{qE}{m} \frac{x^2}{v_0^2}$

Solving for the initial speed,

$v_0 = \sqrt{\frac{qEx^2}{2my}}$

The proton just misses one of the plate when

x = 5.60 cm = 0.056 m (length of the plates)

y = 0.25 cm = 0.0025 m (half the distance between the plates)

Therefore, we find the initial speed:

$v=\sqrt{\frac{(1.6\cdot 10^{-19})(610,000)(0.056)^2}{2(1.67\cdot 10^{-27})(0.0025)}}=6.05\cdot 10^6 m/s$

In order to find the angle, we just need to analyze the horizontal and vertical component of the final velocity of the proton.

The horizontal velocity is constant so it is:

$v_x = v_0 = 6.05\cdot 10^6 m/s$

The vertical velocity is given by:

$v_y^2 - u_y^2 = 2ay$

where:

$u_y=0$ (initial vertical velocity is zero)

$a=\frac{qE}{m}$ (acceleration)

y = 0.0025 m (vertical displacement)

Solving for $v_y$ ,

$v_y = \sqrt{2ay}=\sqrt{2\frac{qEy}{m}}=5.4\cdot 10^5 m/s$

Therefore, the final angle of the velocity with respect to the horizontal is:

$\theta = tan^{-1}(\frac{v_y}{v_x})=tan^{-1}(\frac{5.4\cdot 10^5}{6.05\cdot 10^6})=5.1^{\circ}$

And since the electric field is downward (the proton just misses the lower field), it means that the angle is below the horizontal:

$\theta=-5.1^{\circ}$

Learn more about electric fields:

brainly.com/question/8960054

brainly.com/question/4273177

#LearnwithBrainly

8 0

3 years ago

By how many degrees fahrenheit can the temperature of one metric ton of water be raised with the addition of 110 thousand btus o

Svetllana [295]

1 BTU mean 1 degree of F increased for 1 pound mass. Since the mass unit is in kg that means you need to convert it into pound. One metric ton means 1000kg and 1 kg mean 2.20462lb, then the water mass is: 1000kg x 2.20462lb/kg= 2204.62lb.

You are putting 110,000 btus of heat, so the calculation would be

Temperature increase= energy/mass = 110000btus/ 2204.62lb= 49.9 degree

5 0

4 years ago

Explain how all three of Newton’s Laws of Motion apply to weightlifting.

Lubov Fominskaja [6]

Answer:

Newton's first law, an object will stay at rest only if there are no external forces acting on the object or if the net external force acting on the object is zero. Since the barbell is at rest (not moving), the net external force acting on it must be zero

Newton's Second Law of Motion via the equation f = ma, or put differently, force is equal to mass multiplied by acceleration. To generate more force, we must either increase mass or acceleration (or both)

Newton's Third Law of Motion is known as the equal and opposite reaction principle

7 0

4 years ago

URGENT. Please help.

exis [7]

1). c ... 2). d ... 3). a ... 4). d ... 5). c ... 6). a

7). b-mass ... c-m/s ... d-Newton's 1st ... e-Newton's 2nd

6 0

3 years ago

1 pts

Nuetrik [128]

Answer:

The leaf cells would be unable to convert the sun's energy to make food.

Explanation:

The chloroplast in the leaf are used to make food for the plant. If the leaf loses its chloroplast, the leaf with not be able to use solar energy to manufacture their food.

During photosynthesis, green plants manufacture their food.
They use sunlight to cause a reaction between carbon dioxide and water.
The sunlight is trapped using chlorophyll present in the leaf.
In the absence of the chlorophyll contained in the chloroplast, no solar energy would be generated to cause the reaction to take place.

4 0

3 years ago