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3 years ago

According to our modern understanding, what is a nova?

1 answer:

3 0

A nova is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star, that slowly fades over several weeks or many months. Causes of the dramatic appearance of a nova vary, depending on the circumstances of the two progenitor stars

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You are at the carnival with you your little brother and you decide to ride the bumper cars for fun. You each get in a different

Aliun [14]

Answer:

a) The equation is $(m_{b}+m_{c} )u_{b} = (m_{y}+m_{c} )v_{y} + (m_{b}+m_{c} )v_{b}$

b) Your velocity after collision is 2.64 m/s

c) The force you felt is 7392 N

d) you and your brother undergo an equal amount of acceleration

Explanation:

Your mass $m_{y}$ = 60 kg

your brother's mass $m_{b}$ = 30 kg

mass of the car $m_{c}$ = 80 kg

your initial speed $u_{y}$ = 0 m/s (since you've not started moving yet)

your brother's initial velocity $u_{b}$ = 3 m/s

your final speed $v_{y}$ after collision = ?

your brother's final speed $v_{b}$ after collision = ?

a) equations you need to use to figure out how fast you and your brother are moving after the collision is

$(m_{y}+m_{c} )u_{y} + (m_{b}+m_{c} )u_{b} = (m_{y}+m_{c} )v_{y} + (m_{b}+m_{c} )v_{b}$

but $u_{y}$ = 0 m/s

the equation reduces to

$(m_{b}+m_{c} )u_{b} = (m_{y}+m_{c} )v_{y} + (m_{b}+m_{c} )v_{b}$

b) if your little brother reverses with velocity of 0.36 m/s it means

$v_{b}$ = -0.36 m/s (the reverse means it travels in the opposite direction)

then, imputing values into the equation, we'll have

$(m_{b}+m_{c} )u_{b} = (m_{y}+m_{c} )v_{y} + (m_{b}+m_{c} )v_{b}$

(30 + 80)3 = (60 + 80) $v_{y}$ + (30 + 80)(-0.36)

330 = 140 $v_{y}$ - 39.6

369.6 = 140 $v_{y}$

$v_{y}$ = 369.6/140 = 2.64 m/s

This means you will also reverse with a velocity of 2.64 m/s

c) your initial momentum = 0 since you started from rest

your final momentum = (total mass) x (final velocity)

==> (60 + 80) x 2.64 = 369.6 kg-m/s

If the collision lasted for 0.05 s,

then force exerted on you = (change in momentum) ÷ (time collision lasted)

force on you = ( 369.6 - 0) ÷ 0.05 = 7392 N

d) you changed velocity from 0 m/s to 2.64 m/s in 0.05 s

your acceleration is (2.64 - 0)/0.05 = 52.8 m/s^2

your brother changed velocity from 3 m/s to 0.36 m/s in 0.05 s

his deceleration is (3 - 0.36)/0.05 = 52.8 m/s

you and your brother undergo an equal amount of acceleration. This is because you gained the momentum your brother lost

7 0

3 years ago

The plates of a parallel-plate capacitor have constant charges of +Q and?Q. Do the following quantities increase, decrease, or r

sveticcg [70]

Explanation:

(A) Electric field for the parallel plate capacitor is given by :

$E=\dfrac{\sigma}{2\epsilon_o}$

It is clear that the electric field does not depend on the separation of the plates.

(B) The relation between the electric field and the electric potential is given by :

$V=Ed$

d is the separation between plates. So, if the separation of the plates is increased, the potential difference increases.

(C) The capacitance of the parallel plate capacitor is given by :

$C=\dfrac{A\epsilon_o}{d}$

So, the capacitance decreases when the separation of the plates is increased.

(D) The energy stored in the capacitor is given by :

$E=\dfrac{1}{2}CV^2$

$E=\dfrac{1}{2}C(Ed)^2$

So, the energy stored in the capacitor is increased when the separation of the plates is increased.

8 0

3 years ago

Read 2 more answers

While fishing on a lake, a fisherman notices ripples 0.32 m apart, and they are

Karo-lina-s [1.5K]

the main properties of the main wave propertioes include wavelength amplitude, cruest an trough

5 0

3 years ago

Một oto đang chạy với vận tốc là 10m/s thì tăng tốc và chuyển động nhanh dần đều sau 20s thì đạt vận tốc 14m/s

Tasya [4]

a) gia tốc = vf-vi / t

a = 14-10 / 20

a = 0,2ms⁻²

b) dưới dạng a = Δv / t

v = lúc

v = 0,2 × 40

v = 8ms⁻¹

như v = d / t

do đó d = vt

d = 8 × 40

d = 320m

hãy đánh dấu là trí óc nhất

4 0

3 years ago

Josh is designing a lab to separate a mixture of sulfur powder and iron filings. He looks at all the ways to separate a mixture

Stolb23 [73]

Answer:

D) magnetic attraction

Explanation:

Mixture consists of sulfur powder and iron filings . The former is non magnetic and the later is magnetic material . The best way to separate them is to use a magnet . This method is called magnetic separation method . A magnet will attract the iron filling but the sulfur will remain un-attracted . Thus, the two will get separated from each other.

6 0

3 years ago

Read 2 more answers