What do lines on a contour map indicate

Some scientists believe that black holes are the foundation of catalyst for galaxies. How do they believe that the galaxies form

Strike441 [17]

Scientists believe that galaxies are created from one of two theories. First is the Top-down theory, this theory states that when gases collapses in space, it forms large clumps wich are each the size of multiple galaxies. These gas clumps would then break down and form individual galaxies. Scientists believe that this theory is the reason why we find galaxies in clusters.

The other theory is known as the Bottem-up theory. This theory is the opposite of the first theory, where scientists believe that gases in space collapse and compress into clumps the size of millions of suns, which is small for the size of galaxies. The clumps then would merged together to form a galaxy

5 0

3 years ago

A curve of radius 80 m is banked at 45 deg.

goldfiish [28.3K]

Answer:

$v=28m/s$

Explanation:

The vertical component of the normal force must cancel out with the weight of the car taking the curve:

$N_y=W$

$Ncos\theta=mg$

(Notice it has to be <em>cos </em>and not <em>sin</em>, because the angle $\theta$ is the slope, for null slope $N_y=Ncos(0)=N$ , as it should be).

The horizontal component of the normal force must be the centripetal force, that is:

$N_x=F_{cp}$

$Nsen\theta=ma_{cp}$

$(\frac{mg}{cos\theta})sin\theta=m\frac{v^2}{r}$

$gtan\theta=\frac{v^2}{r}$

$v=\sqrt{grtan\theta}=\sqrt{(9.8m/s^2)(80m)tan(45^{\circ})}=28m/s$

4 0

3 years ago

The speed limit on a highway is 65 miles per hour. a driver wants to travel 487 miles along the highway in the next 9.8 hours. w

topjm [15]

1) 487 miles / 65 miles per hour = 7.5h at max speed
2) 9.8h - 7.5h = 2.3h rest time avaliable

7 0

3 years ago

During drum brake shoe installation, Technician A says the parking brake rear cable and conduit tension should be checked whenev

cestrela7 [59]

Answer: Technician A is correct.

Explanation:

It is very advisable to check the parking brake rear cable and conduit tension should be checked whenever the rear drum brakes are removed as a precautionary measure to detect any faults and check that they are in perfect working condition.

Technician B is wrong because specific anti-seize grease must be used for lubricating the backing plate shoe pads and not just any grease.

6 0

3 years ago

Read 2 more answers

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. But she does have devices to m

Anarel [89]

Answer:

78.4 kg

225.792 J

Explanation:

$m_1$ = Mass of person = 78.4 kg

$m_2$ = Mass of canister = 0.005 kg

$u_1$ = Initial Velocity of person = 0 m/s

$u_2$ = Initial Velocity of canister = 3.6 m/s

$v_1$ = Final Velocity of person = 2.4 m/s

$v_2$ = Final Velocity of canister = 1.2 m/s

In this system the linear momentum is conserved

$m_2u_2=m_2v_2+m_1v_1\\\Rightarrow m_2=\frac{m_1v_1}{u_2-v_2}\\\Rightarrow m_2=\frac{78.4\times 2.4}{3.6-1.2}\\\Rightarrow\\\Rightarrow m_2=78.4\ kg$

The mass of the canister is 78.4 kg

Kinetic energy is given by

$K={\tfrac {1}{2}}m_{1}u_{1}^{2}+{\tfrac {1}{2}}m_{2}u_{2}^{2}-\left({\tfrac {1}{2}}m_{1}v_{1}^{2}+{\tfrac {1}{2}}m_{2}v_{2}^{2}\right)\\\Rightarrow K={\tfrac {1}{2}}78.4\times 0^{2}+{\tfrac {1}{2}}78.4\times 3.6^{2}-{\tfrac {1}{2}}78.4\times 2.4^{2}-{\tfrac {1}{2}}78.4\times 1.2^{2}\\\Rightarrow K=225.792\ J$

The energy lost in the collision is 225.792 J

8 0

3 years ago