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4 years ago

Which question will help tell if a wave is an electromagnetic wave or a

Physics

1 answer:

timofeeve [1]3 years ago

6 0

Answer:

Can the wave travel between the Sun and Earth?

Can the wave travel between a gas and a liquid?

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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

Two blocks with masses m1=0.25kg and m2=1.4kg approach each other along a horizontal, frictionless track. The initial velocities

Alina [70]

Answer:

The energy would remain equal to that of the initial kinetic energy since it is a frictionless surface. However if it is an inelastic collision then energy would be lost due to sound and heat.

Explanation:

4 0

4 years ago

Please help and explain if you can

swat32

Answer:

I think it is the last one

Hot air rising and cool air sinking.

Explanation:I am not 100% sure. I just think the hot air rises bc evaporation.

Good luck. : )

5 0

3 years ago

A car, initially traveling at 81.8 mi/h, slows to rest in 7.1 s. What is the car's acceleration?

maksim [4K]

Answer:

a = -16.9 ft/s²

Explanation:

81.8 mi/hr(5280 ft/mi / 3600s/hr) = 120 ft/s

a = Δv/t = (0 - 120) / 7.1 = -16.9 ft/s²

if the initial direction is taken as the positive direction.

5 0

3 years ago

The current in a wire is 4.00A. How much time is needed for 1 mole of electrons (6.02×1023 electrons) to pass a point in the wir

scZoUnD [109]

Answer:

t= 24080 s

Explanation:

Given that

Current in the wire ,I = 4 A

The charge ,q = 6.02 x 10²³ e C

We know that

$I=\dfrac{q}{t}$

I=Current

q=Charge

t=time

$t=\dfrac{q}{I}$

Now by putting the values in the above equation we get'

$t=\dfrac{6.02\times 10^{23}\times 1.6\times 10^{-19}}{4}\ s$

t= 24080 s

8 0

3 years ago