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A car moving with a velocity 15m/s and accelerating by 5m/s² attempts to reach a car moving with 30 m/s velocity.What distance s

Firlakuza [10]

I think A is correct

4 0

2 years ago

an astronaut on an eva has wandered dangerously far away from the shuttle. she has also exhausted all the fuel in her jet pack.

V125BC [204]

The conservation of the momentum allows to find the result of how the astronaut can return to the spacecraft is:

Throwing the thruster away from the ship.

The momentum is defined as the product of the mass and the velocity of the body, for isolated systems the momentum is conserved. If we define the system as consisting of the astronaut and the evo propellant, this system is isolated and the internal forces become zero. Let's find the moment in two moments.

Initial instant. Astronaut and thrust together.

p₀ = 0

Final moment. The astronaut now the thruster in the opposite direction of the ship.

$m_f$ = m v + M v '

where m is propellant mass and M the astronaut mass.

As the moment is preserved.

0 = m v + M v ’

v ’= $- \frac{m}{M} \ v$

We can see that the astronaut's speed is in the opposite direction to the propeller, that is, in the direction of the ship.

The magnitude of the velocity is given by the relationship between the masses.

In conclusion, using the conservation of the momentun we can find the result of how the astronaut can return to the ship is:

Throwing the thruster away from the ship.

Learn more here: brainly.com/question/14798485

5 0

2 years ago

A pendulum is formed by taking a 2.0 kg mass and hanging it from the ceiling using a steel wire with a diameter of 1.1 mm. it is

Lera25 [3.4K]

Answer: 1.39 s

Explanation:

We can solve this problem with the following equations:

$\frac{\Delta l}{l_{o}}=\frac{F}{AY}$ (1)

$T=2 \pi \sqrt{\frac{l_{o}}{g}}$ (2)

Where:

$\Delta l=0.05 mm=5(10)^{-5} m$ is the length the steel wire streches (taking into account 1mm=0.001 m)

$l_{o}$ is the length of the steel wire before being streched

$F=mg=(2 kg)(9.8 m/s^{2})=19.6 N$ is the force due gravity (the weight) acting on the pendulum with mass $m=2 kg$

$A$ is the transversal area of the wire

$Y=2(10)^{11} Pa$ is the Young modulus for steel

$T$ is the period of the pendulum

$g=9.8 m/s^{2}$ is the acceleration due gravity

Knowing this, let's begin by finding $A$ :

$A=\pi r^{2}=\pi (\frac{d}{2})^{2}=\pi \frac{d^{2}}{4}$ (3)

Where $d=1.1 mm=0.0011 m$ is the diameter of the wire

$A=\pi \frac{(0.0011 m)^{2}}{4}$ (4)

$A=9.5(10)^{-7}m^{2}$ (5)

Knowing this area we can isolate $l_{o}$ from (1):

$l_{o}=\frac{\Delta l AY}{F}$ (6)

And substitute $l_{o}$ in (2):

$T=2 \pi \sqrt{\frac{\frac{\Delta l AY}{F}}{g}}$ (7)

$T=2 \pi \sqrt{\frac{\frac{(5(10)^{-5} m)(9.5(10)^{-7}m^{2})(2(10)^{11} Pa)}{2(10)^{11} Pa}}{9.8 m/s^{2}}}$ (8)

Finally:

$T=1.39 s$

3 0

3 years ago

For each pair of terms below, write a sentence that summarizes how they are different.

Maksim231197 [3]

Answer:

Thermal expansion ,thermal contraction

Explanation:

They are different because it has different cause and chemical reactions

thermal contraction is a chemical reaction

5 0

2 years ago

which force will decrease if the surface of a ramp is made smoother. gravity, magnetism, friction, or electricity

Leno4ka [110]

Friction will decrease

3 0

3 years ago

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