Question 16 of 25

Degger [83]

it's def. TRUE. i got the same question and i got it right

6 0

3 years ago

A distant galaxy is determined to be 150 million light years distant and moving away from us; using the Hubble law determine its

dlinn [17]

Your question kind of petered out there towards the end and you didn't specify
the terms, so I'll pick my own.

The "Hubble Constant" hasn't yet been pinned down precisely, so let's pick a
round number that's in the neighborhood of the last 20 years of measurements:

   <em>70 km per second per megaparsec</em>.

We'll also need to know that 1 parsec = about 3.262 light years.

So the speed of your receding galaxy is

   (Distance in LY) x (1 megaparsec / 3,262,000 LY) x (70 km/sec-mpsc) =

      (150 million) x (1 / 3,262,000) x (70 km/sec) =

   <em>3,219 km/sec </em>in the direction away from us (rounded)

4 0

3 years ago

A box of Thanksgiving presents slides across a waxy floor at 20m/s. It comes to a stop in 4 seconds. What distance did the box t

mars1129 [50]

Answer:

V = d/t = 20

20=d/4 so d = 80

6 0

3 years ago

A block is released from rest, at a height h, and allowed to slide down an inclined plane. There is friction on the plane. At th

GREYUIT [131]

Here the block has two work done on it

1. Work done by gravity

2. Work done by friction force

So here it start from height "h" and then again raise to height hA after compressing the spring

So work done by the gravity is given as

$W_g = m_A g(h - h_A)$

Now work done by the friction force is to be calculated by finding total path length because friction force is a non conservative force and its work depends on total path

$W_f = -(\mu m_A g cos\theta)(\frac{h}{sin\theta} + \frac{h_A}{sin\theta})$