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zvonat [6]
3 years ago
6

By looking closely at how stars and galaxies are moving away from other,what have astronomers been able to calculate

Physics
1 answer:
AnnyKZ [126]3 years ago
3 0

it would have to be c. the age of the universe and the rate at which the universe is expanding cause it can't just be one of the others only

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A sandbag motionless in outer space is hit by a three-times-as massive sandbag moving at 12 m/s. They stick together. This is an
vekshin1

Answer:

This is an example of inelastic collision and it loses zero(0) % of initial kinetic energy

Explanation:

Let the mass of the motionless sandbag = m₁

Let the mass of the moving sandbag = m₂ = 3m₁

initial velocity of the motionless sandbag, u₁ = 0

initial velocity of the moving sandbag, u₂ = 12 m/s

Let their final velocity, = v

Collision between two particles can either be elastic or inelastic.

Since they stick together after the impact, then the collision is inelastic

Apply the principle of conservation of linear momentum;

Initial kinetic energy = final kinetic energy

¹/₂m₁u₁² + ¹/₂m₂u₂² = ¹/₂v²(m₁ + m₂)

¹/₂m₁(0)² + ¹/₂(3m₁)(12)² = ¹/₂v²(m₁+3m₁)

216m₁ = 2m₁ v²

v² = 108

v = √108

v = 10.392 m/s

Change in kinetic energy = Final kinetic energy - initial kinetic energy

Initial Kinetic energy, KE₁ = ¹/₂m₁u₁² + ¹/₂m₂u₂²

                                   KE₁ = ¹/₂m₁(0)² + ¹/₂(3m₁)(12)²

                                   KE₁ = 216m₁ J

Final kinetic energy, KE₂ = ¹/₂v²(m₁ + m₂)

                                  KE₂ = ¹/₂(108)(m₁ + 3m₁)

                                  KE₂ = 216m₁ J

ΔKE = KE₂ - KE₁ =  216m₁ J -  216m₁ J = 0%

Therefore, this is an example of inelastic collision and it loses zero(0) % of initial kinetic energy

4 0
3 years ago
What is physics? Why is it important in our life​
-Dominant- [34]

Answer:

It helps us to know or be aware of some things that happen regular and teaches us about laws that guide us

8 0
4 years ago
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A machine is supplied Energy at a rate of 4000 W and does useful work at a rate of 3760 W. What is the efficiency of the machine
ICE Princess25 [194]
The efficiency of a machine is the ratio between the output power and the power in input:
\epsilon =  \frac{P_{out}}{P_{in}}
in our problem, the output power is 3760 W while the input power is 4000 W, so the efficiency is
\epsilon =  \frac{3760 W}{4000 W} =0.94
So the efficiency of the machine is 94%.
6 0
3 years ago
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A sound wave can be considered as a displacement wave or a pressure wave? What phase difference exists between the displacement
netineya [11]
Where the displacement is a maximum the pressure is a minimum.
Where the displacement is zero, the pressure is a maximum.
3 0
4 years ago
GIVING BRAINLIEST!!!!
Likurg_2 [28]

Answer:

1. Pecan tree 1 and pecan tree 4

2. I don't know

Explanation:

6 0
3 years ago
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