5) Choose the correct statement about the waves shown below.

A car traveling at 38 m/s starts to decelerate steadily. It comes to a complete stop in 10 seconds. What is its acceleration?

asambeis [7]

a=v/t

a=38/10

a=-3.8 m/s^2

You put the negative in front of 3.8 because it decelerated.

Hope it helps and is correct :)

6 0

3 years ago

A fox is 7 meters from the base of a tree that is 15 m tall. A nest of owls is at the top of the tree. One of the owlets tosses

mamaluj [8]

Refer to the diagram shown below.

In this analysis, wind resistance is ignored, and g = 9.8 m/s².

The meat falls with zero vertical velocity, therefore the time, t, before the meat hits the ground is
$\frac{1}{2}*(9.8 \, \frac{m}{s^{2}})*(t \, s)^{2} = (15 \, m) \\ t= \sqrt{ \frac{15}{4.9} }= 1.75 \, s$

If the fox catches the meat before it hits the ground, then the fox should travel a horizontal distance d in the same time that the meat travels a horizontal distance (7 -d).
The meat travels a distance of
7 - d = (1.2 m/s)*(1.75 s) = 2.1 m
or
d = 4.9 m

Let v = velocity of the fox when it catches the meat.
If the acceleration of the fox is a m/s², then
v = 1.75a
Also,
$d= \frac{1}{2} *(a \, \frac{m}{s^{2}} )*(1.75 \, s)^{2} = \frac{1}{2}( \frac{v}{1.75})^{2}*(1.75^{2}) \\ 4.9 = 0.875v^{2} \\ v^{2} = 5.6 \\ v = 2.366 \, m/s$

Answer: 2.37 m/s (nearest hundredth)

5 0

3 years ago

The energy (such as light and heat) released by the Sun is produced by nuclear reactions in the core of the Sun, which convert h

Yanka [14]

Answer:

<em>the mass of one helium nucleus should be</em> <em>less than the mass of four hydrogen nuclei.</em>

Explanation:

Deep inside the core of the Sun, enough protons can collide into each other with enough speed that they stick together to form a helium nucleus and generate a tremendous amount of energy at the same time. This process is called nuclear fusion.

The mass-to-energy conversion is described by Einstein's famous equation:

E = mc2, or, in words, energy equals mass times the square of the velocity of light. Because the velocity of light is a very large number, this equation says that lots of energy can be gained from using up a modest amount of mass.

Photons In the proton-proton chain reaction, hydrogen nuclei are converted to helium nuclei through a number of intermediates. The reactions produce high-energy photons (gamma rays) that move through the "radiative layer" surrounding the core. This layer takes up 60 percent of the radius of the Sun. It takes a million years for energy to get through this layer into the "convective layer", because the photons are constantly intercepted, absorbed and re-emitted. In the core, the helium nuclei make up 62% of the mass (the rest is still hydrogen). The radiative and convective layers have about 72% hydrogen, 26% helium, and 2% heavier elements (by mass). The energy produced by fusion is then transported to the solar surface and emitted as light or ejected as high-energy particles.

3 0

3 years ago

The derived unit for pressure

olga2289 [7]

Answer:

pascal

Explanation:

7 0

3 years ago

Read 2 more answers

Eric has a mass of 80 kgkg. He is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2m/s2. What is the

kolezko [41]

Answer:

The answer will be 936 N.

Explanation:

Given that

m = 80 kg

Acceleration of the elevator , a= 1.7 m/s² ( upward)

The gravity force on the mass = m g

The reading on the scale = F N

Now by applying the Newton's second law

F - m g = ma

F= m g + m a

F= m ( g +a )

F= 80 ( 10 + 1.7 ) N ( take g= 10 m/s²)

F=80 x 11.7 N

F= 936 N

Therefore the reading on the scale will be 936 N.

The answer will be 936 N.

5 0

3 years ago