In space, astronauts use an electrical medium to talk to each other... Why??<br><br>

In a pulley system, two blocks are connected by a rope as shown below. The coefficient of static friction between block A and th

umka21 [38]

Hi there!

We can begin by doing a summation of forces for each block.

Block A:

This block has the force of tension (in direction of acceleration +) and static friction (opposite direction -) acting on it. Thus:

$\Sigma F_A = T - F_s\\\\m_Aa = T - \mu m_Ag$

Block B:

This block has the force of tension (opposite of acc. -) and gravity (in direction of acc +), working on it.

$\Sigma F_B = m_Bg - T\\\\ m_Ba = m_Bg - T$

Add both of the expressions and solve for the maximum mass of Block B.

$\Sigma F = m_Bg - T + T - \mu m_Ag\\\\a(m_A + m_B) = m_Bg - \mu m_Ag$

To find the minimum value, we can set a = 0, so:

$0 = m_Bg - \mu m_Ag\\\\\mu m_Ag = m_B g\\\\0.8(20)(9.8) = m_B (9.8)\\\\m_B = \frac{0.8(20)(9.8)}{9.8)} = \boxed{16 kg}$

The block must weigh <u>> 16 kg</u> for block A to move.

5 0

3 years ago

Interactive Solution 26.7 offers one model for problems like this one. In a certain time, light travels 3.97 km in a vacuum. Dur

jenyasd209 [6]

Answer:

Refractive Index = 1.52

Explanation:

As we know speed of light in vaccum is 3 x 10^8 meters per second and distance tavelled by light is 3.97 km or 397000m.

Time taken by light in vaccum = distance / speed = 397000 / 3 x 10^8 = 1.323 x 10^-3 s

Speed of light in liquid = distance / time taken = 261000 / 1.323 x 10^-3 = 197278911 ms^-1 = 1.972 x 10^ 8 ms^-1

According to Snell's law

Refractive index = speed of light in vaccum / speed of light in medium = 3 x 10^8 ms^-1 / 1.972 x 10^8 ms^-1 = 1.52

4 0

3 years ago

Plsss helpp will give brainliest!!!

Alexandra [31]

Answer:

1. Flexibility.

2. Muscular Fitness

3. Cardiovascular Fitness

4. Cardiovascular Fitness

5. Flexibility

6. Muscular Fitness

7. Cardiovascular Fitness

6 0

3 years ago

Two identical cars are traveling at the same speed. One is heading due east and the other due north, as the drawing shows. Which

VMariaS [17]

Answer:

A) They have the same kinetic energies, but different momenta.

Explanation:

Before answering, let's remind that:

- Kinetic energy is a scalar quantity, which is given by:

$K=\frac{1}{2}mv^2$

where m is the mass of the object and v is the speed.

- Momentum is a vector quantity, whose magnitude is given by:

$p=mv$

where m is the mass of the object and v is the velocity, and whose direction is the same as the velocity.

By looking at the two definitions, we can say that:

- the two cars have same kinetic energy, because they have same mass and same speed

- The two cars have different momenta, because they do not have same velocity (in fact, their directions are different, since one is heading east and the other one is heading north)

6 0

3 years ago

What happen when you take off your clothes very quickly

BARSIC [14]

Answer:

Nothing

Explain

Nothing happenes when you take off your cloths quickly.

Scientificly nothing really happnes.

4 0

3 years ago

In space, astronauts use an electrical medium to talk to each other... Why??​

In space, astronauts use an electrical medium to talk to each other... Why??