The interstellar medium is composed of _______

An object is falling from a height of 7.5 meters. At what height will it’s velocity be 7 meters/second?

Nady [450]

One of the equations of gravity is this:
${v}^{2} = {u}^{2} + 2gh$
Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
h = height of object

Substitute for the values and you should have something like this
${7}^{2} = {0}^{2} + 2 \times 10 \times h$
$49 = 0 + 20h$
$h = \frac{49}{20}$
$h = 2.5m$

6 0

2 years ago

If a crow flies west for 60 km and then south for 45 km, what is the direction of its displacement?

son4ous [18]

That's 105 km that he flew, or 65.2 miles ! I'm absolutely positive
that the crow must have landed and gotten some rest when you
weren't looking. But that had no effect on his displacement when
he got where he was going, so we can continue to solve the problem:

The displacement is the distance and direction from the place
where the crow took off to the place where he landed.

-- It's distance is the hypotenuse of the right triangle whose legs
are 60 km and 45 km.

D² = (60 km)² + (45 km)²

=    3,600 km² + 2,025 km² = 5,625 km²

   D = √(5625 km²) = 75 km .

-- It's direction is the angle whose tangent is (45 S / 60 W).

   tan⁻¹ (45/60) = tan⁻¹ (0.75) = 36.9° south of west

   = 53.1° west of south.

   = not exactly southwest but close.

7 0

2 years ago

Whats it called when a force can change the shape of an object?

alekssr [168]

Force applied causes deformation in the object. It changes the relative positions of constituent particles in the crystal lattice.
As soon as that happens, the interatomic or intermolecular forces come into play and they, tend to restore the solid back to it's original shape.

This restoring force per unit area is called Stress . When external forces are removed, the internal forces tend to restore the solid back.
This property is called Elasticity .

However, no material is perfectly elastic and what happens is that, the body is not able to restore itself completely.

3 0

2 years ago

Read 2 more answers

(a) Calculate the force (in N) needed to bring a 1100 kg car to rest from a speed of 85.0 km/h in a distance of 125 m (a fairly

nasty-shy [4]

(a) -2451 N

We can start by calculating the acceleration of the car. We have:

$u=85.0 km/h = 23.6 m/s$ is the initial velocity