John slides down a hill at a 4 m height initially at rest. If all energy is conserved and friction is excluded, what is John's velocity at the bottom of the ramp?

Answer:

I think the answer is B I hope this helps also Im sorry If I'm wrong

Answer:

D. Violence

Explanation:

Violence is the threat of or actual use of physical force against oneself or another person. Violence often results in injury or death.

Answer:

D.Violence

Explanation:

You're welcome!

Answer:

mass of that object is = 30 × 29 = 870N

Answer:

Distance.

Explanation:

Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point i.e the amount of distance covered by the physical object.

This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.

Mathematically, the motion of an object is described in terms of acceleration, time, distance, speed, velocity, displacement, position, etc.

Hence, distance is the measured value (always positive) from one point to another.

Mathematically, distance is given by the formula;

Distance = speed * time

Also, the S.I unit for measuring the distance covered by a physical object is meters.

Answer:

the average speed of the swimmer is 0.069 m/s.

Explanation:

Given;

complete distance around the park pine, d = 25 m

total lap completed, = 20 laps

time of laps completion, t = 7200 s

The total distance completed by the swimmer = 20 x 25 = 500 m

The average speed of the swimmer = distance / time

                                                            = (500 m) / (7200 s)

                                                            = 0.069 m/s.

Therefore, the average speed of the swimmer is 0.069 m/s.

Answer:

no i did not observe anything

Explanation:

Answer:

It is important to have a range of tools that can measure all parts of the electromagnetic spectrum because electromagnetic spectrum have different radiations such as infrared, visible light, ultraviolet, radio waves, microwaves, X-rays and gamma rays. Each of these radiation requires different instrument for their measurement. So that's why a range of tools are needed to measure electromagnetic spectrum.

Answer: mirror neurons are the reason people usually reflect the behavior of those around them and have been linked to the ability to empathize. People are attracted to happy people because it seems to boost our mood.

Explanation:

Answer:

Some psychologists think that you can trick your brain into feeling happy by acting happy. Acting happy might actually make one happy by mirror neurons. This is the reason people usually reflect the behavior of those around them and have been linked to the ability to empathize. People are attracted to happy people because it seems to boost our mood. The three components of emotion are cognitive, physiological, and behavioral. There is actually some scientific evidence to suggest that smiling, even when you are not feeling happy, can make you happy. This idea is called the facial feedback hypothesis. Happiness, and smiling, can also be contagious and make others around them want to smile. People often mimic the facial expressions of others.

Explanation:

100% on Edge 2023!! You're welcome :) :) :) :)

Answer:

no lo se

Explanation:

Supposing a steam governor has two balls that are each rotating with a tangential speed of 3.7 m/s. The balls are 0.10 m from the rotation axis, and the centripetal force on each ball is 670 N. Then the mass of one of the balls is 4.89 kg.

''Centripetal force is force acting on a body performing circular motion, which is along radius of the circle and directed towards the center of circle"

since centripetal force acts at right angle to the tangential velocity of the body, there is no displacement in the direction of the force, hence no work done. It has newton(N) as Si unit.

centripetal force is given by,

F= mv²÷r

Where m is mass of the body

v is velocity of the body

r is radius of circle at which body is moving.

Given

velocity v = 3.7 m/s

radius r = 0.10 m

centripetal force F = 670N

mass = ?

from formula we can write,

670 = m(3.7)²÷0.10

m= (670×0.10)÷(3.7)²

m = 4.89 kg

Hence mass of one of the balls is 4.89 kg

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Answer:

B

Explanation:

The object won't stay in the same place if its moving

Explanation:

B) Measure it's change in position.

The organism that is used to manufacture human insulin is known as the bacteria E. Coli. Thus, the correct option for this question is C.

The function of human insulin is to maintain the blood sugar level by converting the active form of sugar which is glucose into the stored form of glycogen in order to maintain the blood sugar level.

In this modern era of science and technology, recombinant human insulin is mainly synthesized or produced with the help of organisms like E. Coli which is classified in the category of bacteria, and Saccharomyces cerevisiae which is classified in the category of unicellular fungus.

Therefore, the organism that is used to manufacture human insulin is known as the bacteria E. Coli. Thus, the correct option for this question is C.

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Answer:

Explanation: positive

Answer: The metal is iron.

Explanation:

We have 59.1 grams of a given metal.

We need 890.9 joules of energy to heat the metal from 26.1°C to 59.6°C

First, we need to see the net increase in temperature, which is equal to the difference between the final temperature and the initial temperature.

ΔT = 59.6°C - 26.1°C = 33.5°C

Now we can find the specific heat, which is calculated as:

c = Ε/(ΔT*m)

Where:

E = energy given to the material = 890.9 J

m = mass of the material = 59.1 gr

ΔT = change in temperature = 33.5°C

Replacing these in the above equation we get:

c = 890.9 J/(33.5°C*59.1 gr) = 0.45 J/(gr*°C)

Now we need to look at a table of specific heats and see which metal has this specific heat.

We can see that iron is the best match, so we can assume that the metal is iron.

Answer:

The electron gives up It's extra energy in a form called "photon light" and falls back down to its normal energy level

Explanation:

The bicycle is a distance x away from the wall at time t according to

x = 10 m + (4 m/s) t + 1/2 (12 m/s²) t ²

so that after t = 8 s, it will be

x = 10 m + (4 m/s) (8 s) + 1/2 (12 m/s²) (8 s)² = 426 m

away from the wall.

Answer:

Well, it's because the air offers much greater resistance to the falling motion of the feather than it does to the brick. ... Galileo discovered that objects that are more dense, or have more mass, fall at a faster rate than less dense objects, due to this air resistance. A feather and brick dropped together.

Explanation:

Anwser

The strength of a force is usually expressed by its magnitude. We have also to specify the direction in which a force acts.

Answer:

(A) The magnitude of its angular acceleration 1.09 x 10⁻³ rad/s²

(B) Time of motion 240.2 s

Explanation:

Given;

final angular speed, ωf = 2.5 RPM

angular distance, θ = 5 rev = 5 x 2π = 10π rad

initial angular speed, ωi = 0

final angular speed in rad/s;

[tex]\omega_f = \frac{2.5 \ rev}{min} \times \ \frac{2\pi}{1 \ rev} \times \ \frac{1 \min}{60 s} = 0.2618 \ rad/s \\[/tex]

(A) the magnitude of its angular acceleration(rad/s^2);

[tex]\omega_f^2 = \omega_i^2 + 2\alpha \theta\\\\(0.2618)^2 = 0 + (2\times 10\pi)\alpha\\\\0.0685 = 20\pi \alpha\\\\\alpha = \frac{0.0685}{20\pi} \\\\\alpha = 1.09\times 10^{-3} \ rad/s^2[/tex]

(B) Time of motion;

[tex]\omega_f = \omega_i + \alpha t\\\\0.2618 = 0 + 1.09\times 10^{-3} t\\\\t = \frac{0.2618}{1.09\times 10^{-3}} \\\\t = 240.2 \ s[/tex]

Answer:

0.3kilowatts hours

Explanation:

If you bake a potato in a toaster oven that uses 1.2 kW and oven turned on for 25minutes, to get the amount in kilowatt hour, we will need to convert minutes to hour first

60minutes = 1hr

25minutes = x

60x = 25

x = 25/60 hr

x =

Multiply the time in hr with the power

Amount of kWhr used = 1.2 * 25/60

Amount of kWhr used = 30/60

Amount of kWhr used  = 0.3kilowatts hours

Hence it used 0.3kilowatts hours

No.

Radio, TV, microwave, heat, red, yellow, blue, tanning rays, X-rays, and gamma rays all travel at the same speed.  It's called the "speed of light".

(As long as they're all traveling through the same stuff.)

Answer:

virtual

Explanation:

because the light rays do not meet at the image position

the other options are definitely wrong because

characteristics of a plane mirror images are that,

it is the same size as the object

it is upright

Answer:

B - Virtual

Explanation:

Answer:

more point plzzzzz... eeeeeeeee

A to B in the graph shows the object going at the fastest speed.

In a distance-time graph, the gradient of the line is equal to the speed of the object. The greater the gradient (and the steeper the line) the faster the object is moving.

"The rate of change of position of an object in any direction. Speed is measured as the ratio of distance to the time in which the distance was covered. Speed is a scalar quantity as it has only direction and no magnitude."

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Answer:

B. A well-tested explanation for a widely accepted hypothesis

Explanation:

This is true about a scientific theory going by the fact of it being a well tested explanation. For example, in one of the Newtons law of motion which he stated to be "To every action, there is equal and opposite reaction", the hypothesis has been known till he was able to offer a well tested explanations with calculations showing that, it was actually true.

Answer:

I haven't learnt physics at all yet but I'll try.

After the two cars collide, they move at 6 m/s.

This tells us that the 2nd car which collided with the first car which is 2000 kg is much heavier than the 1st one, if the second one was lighter, the two cars coupled together speed would be much more than just 6 m/s.

Refer to explanation for working.

Explanation:

Now find out how much g or kg is the 2nd car more than the 1st.

2000 ÷ 10 = 200 (I don't really know how to explain this part)

10 - 6 = 4 (Difference for 1st car average speed per second and the coupled cars average speed per second)

200 x 4 = 800

2000 + 800 = 2800 kg

(Final answer)

Answer:

A

Explanation:

if the man doubles his force to 40 and the box was yet to move that means acceleration also doubled so your answer would be A

Answer:

9.39 m/s

Explanation:

Using the y-direction, we can solve for the time t it takes for the cart to reach the ground.

Assume the up direction is positive and the down direction is negative.

Find the constant acceleration equation that contains these four variables.

Substitute known values into this equation.

Multiply and simplify.

Divide both sides of the equation by -4.9.

Square root both sides of the equation.

Now we can use this time t and solve for v₀ in the x-direction. Time is most often our link between vertical and horizontal components of projectile motion.  

List out known variables in the x-direction.

Find the constant acceleration equation that contains these four variables.

Substitute known values into the equation.

Multiply and simplify.

Divide both sides of the equation by 3.194382825.

The cart was rolling at a velocity of 9.39 m/s (initial velocity) when it left the ledge.

Answer:

9.39 m/s

Explanation:

Using the y-direction, we can solve for the time t it takes for the cart to reach the ground.

Assume the up direction is positive and the down direction is negative.

v₀ = 0 m/s

a = -9.8 m/s²

Δy = -50 m

t = ?

Find the constant acceleration equation that contains these four variables.

Δy = v₀t + 1/2at²  

Substitute known values into this equation.

-50 = (0)t + 1/2(-9.8)t²

Multiply and simplify.

-50 = -4.9t²

Divide both sides of the equation by -4.9.

10.20408163 = t²

Square root both sides of the equation.

t = 3.194382825

Now we can use this time t and solve for v₀ in the x-direction. Time is most often our link between vertical and horizontal components of projectile motion.  

List out known variables in the x-direction.

v₀ = ?

t = 3.194382825 s

a = 0 m/s²

Δx = 30 m

Find the constant acceleration equation that contains these four variables.

Δx = v₀t + 1/2at²  

Substitute known values into the equation.

30 = (v₀ · 3.194382825) + 1/2(0)(3.194382825)²

Multiply and simplify.

30 = v₀ · 3.194382825

Divide both sides of the equation by 3.194382825.

v₀ = 9.391485505

The cart was rolling at a velocity of 9.39 m/s (initial velocity) when it left the ledge.

The velocity of the truck changed after changing direction because, velocity is a vector quantity.

Velocity of an object is defined as the rate of change of displacement of the object.

Here,

The the truck driver was driving at 30 mph and when she makes a U-turn, she starts driving at 30 mph in the opposite direction.

The quantity that changed during this change in direction is its velocity.

The speed of the truck will not change due to the change in direction because, speed is a scalar quantity.

But the velocity of the truck is changed due to the change in direction because, the velocity is a vector quantity.

A vector quantity is a quantity that has both magnitude and direction.

Hence,

The velocity of the truck changed after changing direction because, velocity is a vector quantity.

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