A school bus uses petroleum as chemical potential energy. This energy

When objects are forced to vibrate ( like when dropped onto a hard surface), they will do so at their

Marat540 [252]

They'll vibrate at their characteristic resonant frequency. That depends on the material the object is made of and its shape.

3 0

4 years ago

Name 5 machine principles

lidiya [134]

The Wheel & Axle. The wheel has always been considered a major invention in the history of mankind

The Inclined Plane

The Wedge

The Pulley

The Screw

3 0

4 years ago

Two astronauts, each with a mass of 50 kg, are connected by a 7 m massless rope. Initially they are rotating around their center

kiruha [24]

Answer:

The angular velocity is $w_f = 1.531 \ rad/ s$

Explanation:

From the question we are told that

The mass of each astronauts is $m = 50 \ kg$

The initial distance between the two astronauts $d_i = 7 \ m$

Generally the radius is mathematically represented as $r_i = \frac{d_i}{2} = \frac{7}{2} = 3.5 \ m$

The initial angular velocity is $w_1 = 0.5 \ rad /s$

The distance between the two astronauts after the rope is pulled is $d_f = 4 \ m$

Generally the radius is mathematically represented as $r_f = \frac{d_f}{2} = \frac{4}{2} = 2\ m$

Generally from the law of angular momentum conservation we have that

$I_{k_1} w_{k_1}+ I_{p_1} w_{p_1} = I_{k_2} w_{k_2}+ I_{p_2} w_{p_2}$

Here $I_{k_1 }$ is the initial moment of inertia of the first astronauts which is equal to $I_{p_1}$ the initial moment of inertia of the second astronauts So

$I_{k_1} = I_{p_1 } = m * r_i^2$

Also $w_{k_1 }$ is the initial angular velocity of the first astronauts which is equal to $w_{p_1}$ the initial angular velocity of the second astronauts So

$w_{k_1} =w_{p_1 } = w_1$

Here $I_{k_2 }$ is the final moment of inertia of the first astronauts which is equal to $I_{p_2}$ the final moment of inertia of the second astronauts So

$I_{k_2} = I_{p_2} = m * r_f^2$

Also $w_{k_2 }$ is the final angular velocity of the first astronauts which is equal to $w_{p_2}$ the final angular velocity of the second astronauts So

$w_{k_2} =w_{p_2 } = w_2$

So

$mr_i^2 w_1 + mr_i^2 w_1 = mr_f^2 w_2 + mr_f^2 w_2$

=> $2 mr_i^2 w_1 = 2 mr_f^2 w_2$

=> $w_f = \frac{2 * m * r_i^2 w_1}{2 * m * r_f^2 }$

=> $w_f = \frac{3.5^2 * 0.5}{ 2^2 }$

=> $w_f = 1.531 \ rad/ s$

3 0

3 years ago

PLZ SOMEONEE HELPP I’LL MARK BRANLIESTTTT

7nadin3 [17]

Answer:

I'm pretty sure it's 37.5 joules of energy

Explanation:

hope this helps!

8 0

3 years ago

1. Which type of wire would be a better conductor of an electrical current?

Lelechka [254]

Answer:

1. a

2. b

3. b

Explanation:

1.

Resistance is the property of a conductor to offer resistance to the flow of current. The lower the resistance better is the conductivity of wire.

We know that the resistance of a wire depends on several factor which are inter-connected by an equation as:

$R=\rho.\frac{l}{a}$

where:

R = resistance of the wire

$l =$ length of the wire

$a=$ cross sectional area of the wire

from the above relation we observe that

$R\propto l$

$R\propto \frac{1}{a}$

Also when the temperature of the wire is significantly high then the lattice vibration cause obstruction in the path of the flowing charges and reduce the current flow.

2.

As the collision between the electrons and protons increases the speed of the flow of charges will decrease because the opposite charges attract each other and as we know that electrical current is the rate of flow of charge.

3.

Heating up of wire due to sunlight will cause lattice vibration in the conductor and will obstruct the movement of the charges which build up electric current, hence increasing the resistance of conductivity.

7 0

3 years ago