Why is the milky way galaxy not expanding together with the rest of the universe?

Andy is waiting at the signal. As soon as the light turns green, he accelerates his car at a uniform rate of 8.00 meters/second2

lbvjy [14]

-- The car starts from rest, and goes 8 m/s faster every second.

-- After 30 seconds, it's going (30 x 8) = 240 m/s.

-- Its average speed during that 30 sec is (1/2) (0 + 240) = 120 m/s

-- Distance covered in 30 sec at an average speed of 120 m/s

 = 3,600 meters .
___________________________________

The formula that has all of this in it is the formula for
distance covered when accelerating from rest:

 Distance = (1/2) · (acceleration) · (time)²

 = (1/2) · (8 m/s²) · (30 sec)²

 = (4 m/s²) · (900 sec²)

 = 3600 meters.

_________________________________

When you translate these numbers into units for which
we have an intuitive feeling, you find that this problem is
quite bogus, but entertaining nonetheless.

When the light turns green, Andy mashes the pedal to the metal
and covers almost 2.25 miles in 30 seconds.

How does he do that ?

By accelerating at 8 m/s². That's about 0.82 G !

He does zero to 60 mph in 3.4 seconds, and at the end
of the 30 seconds, he's moving at 534 mph !

He doesn't need to worry about getting a speeding ticket.
Police cars and helicopters can't go that fast, and his local
police department doesn't have a jet fighter plane to chase
cars with.

5 0

3 years ago

A 26.0-kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 225 N. For the first 11.0 m th

frozen [14]

Answer:

18 m/s

Explanation:

Force is given by mass × acceleration

F = ma

a = F/m

For the first 11.0 m, there is no friction. Hence, the constant force is applied fully on the crate. The acceleration is

a = 225/26.0 m/s²

By the equation of motion, v² = u² + 2as

where v is the final velocity, u is the initial velocity, a is the acceleration and s is the distance travelled.

Using the values for the first part of the motion,

v² = 0² + 2 × 8.65 × 11.0

v = 13.8 m/s

This is the initial velocity for the second part of the motion. This part has friction of coefficient 0.20.

The frictional force = 0.20 × weight = 0.20 × 26.0 × 9.8 = 50.96 N

The effective force moving the crate in the second motion = 225 - 50.96 N = 174.04 N

This gives an acceleration of 174.04/26.0 = 6.69 m/s².

Using parameters for the equation of motion, v² = u² + 2as

v² = 13.8² + 2 × 6.69 × 10 = 324.24

v = 18 m/s

8 0

4 years ago

Name of compounds a.MgC12 b.Mg3 (PO)2 c.Ca(HCO)2

Vlad1618 [11]

Answer:

a. Magnesium dichloride

b. Magnesium phosphate

c. Calcium hydrogen carbonate

5 0

3 years ago

Why does a magnet attract a steel nail

SVEN [57.7K]

Answer:

The nail will stick to the bar magnet because it will become magnetized, and it's metal. The presence of the nearby north pole rearranges the magnetic domains inside the steel so that their south poles all point toward the north pole of the permanent magnet. As a result, the other end of the nail becomes a north pole.Magnets attract iron due to the influence of their magnetic field upon the iron. ... When exposed to the magnetic field, the atoms begin to align their electrons with the flow of the magnetic field, which makes the iron magnetized as well. This, in turn, creates an attraction between the two magnetized objects.

7 0

3 years ago

1. What net force is required to accelerate a car at a rate of 2 m/s2 if the car has a mass of 3,000 kg?

nataly862011 [7]

Answer:

Net force required to accelerate the car is 6000 N

Explanation:

Force is calculated by the equation, F = Mass × Acceleration

This is based on Newton's Second Law of Motion which states that the force acting on an object is its mass times the acceleration of the object.

Here, mass = 3000 kg and acceleration = 2 m/s²

⇒ Force = Mass × Acceleration

= 3000 × 2 = 6000 N

⇒ F = 6000 N

⇒ M = 3000 kg

⇒ a = 2 m/s²

7 0

3 years ago