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olga nikolaevna [1]

3 years ago

13

If a roller coaster has 50,000 J of potential energy at the top of the first hill, how much kinetic energy does it have at the l

owest point?

1 answer:

Fed [463]3 years ago

4 0

Answer:

50,000 J because of the transformation of energy

Explanation:

You might be interested in

A person weighing 504 Newtons enters an elevator and stands on a scale which reads his weight in Newtons. The elevator starts to

Tomtit [17]

Answer:

942.68 N

Explanation:

Weight of man = 504 N = W

a = Acceleration = 8.53 m/s²

g = Acceleration due to gravity = 9.80 m/s²

Mass of man

$m=\frac{W}{g}=\frac{504}{9.8}$

Weight shown when elevator is being accelerated

$W_n=ma+mg\\\Rightarrow W_n=\frac{504}{9.8}\times 8.53+504\\\Rightarrow W_n=942.68\ N$

Scale reading while the elevator is accelerating upward is 942.68 N.

4 0

3 years ago

Which chart provides the correct number of neutrons for each isotope of tin (Sn)?

Trava [24]

We know, Atomic mass = Atomic number + number of neutrons
Here, Atomic mass - 50 = number of neutrons [ as A.N. = 50 ]

So, According to our info. only option B can be correct, as the difference between atomic mass & number of neutrons is 50, which is atomic number of Tin (Sb)

In short, Your Answer would be Option B

Hope this helps!

6 0

3 years ago

Suppose this comet were to hit the earth at 40000 km/h and fuse with it. by how much would it change our planet's velocity? (the

sattari [20]

<span>change in velocity = final velocity - initial velocity = v - u

for comet:
uc = initial velocity of comet (before impact)
vc = final velocity of comet
mc= mass of comet

uc = 40000 kmph
vc = ?
mc= 10 x 10^14 kg

for probe:

up = initial velocity of probe (before impact)
vp = final velocity of probe
mp= mass of probe

up= 37000 kmph
vp= ?
mp= 372 kg

Now,
by principle of conservation of momentum

(mc x uc) - (mp x up) = (mc x vc) + (mp x vp)

Since probe is in comet after collision, vp= vc = V

then,

(mc x uc) - (mp x up) = V (mc + mp )
V = [(mc x uc) - (mp x up)] / (mc + mp )

= ((10 × 10^14 × 40000) - (372 × 37000)) ÷ ((10 × 10^14) + 372)

= ???

then,

change in velocity of the comet = ??? - (40000) =

</span>

8 0

3 years ago

Suppose you increase your walking speed from 7 m/s to 15 m/s in a period of 2 m. What is your acceleration?

likoan [24]

Acceleration = (change in speed) / (time for the change)

Change in speed = (end speed) - (start speed) = (15 m/s - 7 m/s) = 8 m/s

time for the change = 2 minutes = 120 seconds

Acceleration = (8 m/s) / (120 seconds)

Acceleration = 0.067 m/s²

7 0

3 years ago

A year 11 pupil with a mass of 55kg swinging back on their chair and falling off it at a speed of 0.6m/s. What is his kinetic en

posledela

Answer:

Uk = 9.9 J

Explanation:

To calculate the kinetic energie (Uk), you can make use of this formula:

Uk = 0.5 * m * v²

given m = 55 kg and v = 0.6 m/s

Substituting in the formula gives:

Uk = 0.5 * 55 * (0.6)²

Uk = 0.5 * 55 * 0.36

Uk = 9.9 J

Extra:

Now let's examine the formula in relation to the SI units. <em>If you understand the following, it will give you great insight in how smart Phisics is inter twained by looking at formulas and their standard units. It will save you time in future to convert formulas, if you use the right standard units.</em>

The formula for kinetic energie is:

Uk = 0.5 * m * v²

Standard SI unit for mass m is kg.

Standard SI unit for speed v is m/s.

So v * v = v² and therefore v² must have the standard SI unit of m²/s².

From the formula, you see that the unit of Uk must be kg*m²/s² and since Uk is normally given in J, these both forms must be the same !

The main unit for Uk is the Joule. <em>Now</em><em> </em><em>please</em><em> </em><em>see</em><em> </em><em>the</em><em> </em><em>picture</em><em>,</em><em> </em><em>which</em><em> </em><em>shows</em><em> </em><em>the </em><em>relation</em><em> </em><em>between </em><em>the </em><em>J </em><em>and </em><em>other</em><em> SI units</em><em>.</em><em> </em><em>Please</em><em> </em><em>understand</em><em> </em><em>that</em><em> </em><em>you</em><em> </em><em>can</em><em> </em><em>construct</em><em> </em><em>your</em><em> </em><em>'own'</em><em> </em><em>formulas</em><em> </em><em>based</em><em> </em><em>these</em><em> </em><em>units</em><em>.</em><em> </em><em>Now</em><em> </em><em>here</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>time</em><em> </em><em>saver</em><em>:</em>

Because almost always the right units are <em>given</em> in a question, or because sometimes you can look up a constant in a table with an exotic and seemingly complicated unit, but that says a lot about the formula which must have been some how involved!

<em>By this, I hope you now understand the implication of using the right standard SI units and how that can help you figure out what formula is needed.</em>

3 0

3 years ago