The possible presence of a supermassive black hole at the center of our galaxy has been deduced from

This time, William Tell is shooting at an apple that hangs on a tree (Fig. 3.32). The apple is a horizontal distance of 20.0 m

mart [117]

Answer:

The initial arrow's velocity is 40,9 m/s at 11.9° from the horizontal

Explanation:

In order to find the inital velocity we need to determine its components and the angle that the arrow is launched at.

For horizontal component, we will have:

ν cos(θ)t = x ⇒ cos(θ) = x/νt

For vertical component we will have:

h= v sin(θ)t ₋ gt²÷ 2 ⇒ sin (θ) = h + gt²÷2/νt

From the two equations we got, after noting that the vertical displacement is 3m, we can calculate

tan(θ) = h +gt²÷2/νt/ x÷νt = h+ gt²÷2/x = 3+ 9.8.0.5²÷2/20 = 0.21125

Now we can calculate θ = tan⁻¹(0.21125) ≈ 11.9°

Now that we know the angle we can subtitute at any of the expressions for the two components of the velocity . Let's do this subsitution at the horizontal component:

ν cos(θ)t= x =ν = x/tcos(θ)= 20/ 0.5cos(11.9) ≈ 40.9 m/s.

4 0

3 years ago

When you add heat to wood it burns. The cellulose that makes up wood is converted to carbon dioxide, water vapor, and ash. This

statuscvo [17]

Chemical composition, the element no longer retains the same chemical formula as it did before.

4 0

3 years ago

What is the volume of a 72 g of copper if copper has a density of 9 g/cm3

azamat

Answer:

8 centimetre cube

Explanation:

because volume is equal to mass per densiry

6 0

4 years ago

By what percent does the braking distance of a car decrease, when the speed of the car is reduced by 10.3 percent? Braking dista

likoan [24]

The braking distance is the distance traveled by a car experiencing a braking force until it comes to rest.

Our initial energy is solely kinetic:
$E_i = \frac{1}{2}mv^2$

And, since the car goes to rest, it is no longer in motion. It will have no kinetic energy.
$E_f = 0$

Therefore, there was work done by the braking force.

$W_B = E_f - E_i = -\frac{1}{2}mv^2$

Recall the definition of work:
$W = F\cdot \Delta x$

Or in this case, since the displacement and breaking force are antiparallel:
$W = -F_B\Delta x$

This is equivalent to the dissipation of kinetic energy:
$W = -F_B\Delta x = -\frac{1}{2}mv^2$

Now, to visualize this, let's rearrange the equation to solve for displacement.

$\Delta x =\frac{mv^2}{2F_B}$

There is a direct, SQUARE relationship between necessary braking distance speed.

If the speed was reduced by 10.3 percent, its new speed is only 89.7% percent of the original, so:
$\Delta x' =\frac{m(0.897v)^2}{2F_B}$

$\Delta x' = 0.8046\Delta x$

The reduction by a percentage is:
$1 - 0.8046 = 0.1954 \\\\\boxed{= 19.54\%}$

6 0

2 years ago

All chemical reactions occur at the same rate true or false

SSSSS [86.1K]

Answer:

false

Explanation:

7 0

3 years ago

Read 2 more answers