A B-52 bomber jet flies at a horizontal velocity of 286.2 m/s and at an altitude of 7500 m above the ground.

The time, t, required to drive a fixed distance varies inversely as the speed, r. It takes 9 hr at a speed of 20 km/h to driv

Harlamova29_29 [7]

Answer:

Time=7.84hrs

Explanation:

This is an inverse proportionality questions

Mathematically time t varies as 1/distance d

Hence T= dk/r

But speed r = distance/t

d= r*t= 9*20=180km/hr

We're k= constant of proportionality

At t=9hrs d=180km/hr

Hence k=r*t/d=20*9/1620=0.111

Finding t at at 1620km for 23km/hr

t=1620*0.111/23=7.84hrs

6 0

3 years ago

A 0.50-kg block attached to an ideal spring with a spring constant of 80 N/m oscillates on a horizontal frictionless surface. Th

Taya2010 [7]

Answer:

The greatest extension of the spring is $\bf{0.055~m}$ and the maximum speed of the block is $\bf{0.695~m/s}$ .

Explanation:

Given:

The mass of the block is, $m = 0.50~kg$

The spring constant of the spring is, $k = 80~N/m$

The mechanical energy of the block is, $E = 0.12~J$

When a particle is oscillating in a simple harmonic way, its total energy is given by

$E = \dfrac{1}{2}m\omega^{2}a^{2}~~~~~~~~~~~~~~~~~~~~~~~~~~~(1)$

where $\omega$ is the angular velocity of the mass and $a$ is the amplitude of its motion.

The relation between angular velocity and spring constant is given by

$\omega = \sqrt{\dfrac{k}{m}}~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(2)$

Substituting equation (2) in equation (1), we have

$~~~~~~&& E = \dfrac{1}{2}ka^{2}\\&or,& a = \sqrt{\dfrac{2E}{k}}~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(3)$

Substituting $0.12~J$ for $E$ and $80~N/m$ for $k$ in equation (3), we can write

$a &=& \sqrt{\dfrac{2(0.12~J)}{80~N/m}}\\~~~&=& 0.055~m$

The relation between the maximum velocity and the amplitude is given by

$v_{m} &=& \omega a\\~~~~&=& \sqrt{\dfrac{k}{m}}a~~~~~~~~~~~~~~~~~~~~~~~~~~~~(4)$

Substituting $80~N/m$ for $k$ , $0.50~kg$ for $m$ and $0.055~m$ for $a$ in equation (4), we have

$v_{m} &=& \sqrt{\dfrac{80~N/m}{0.50~kg}}(0.055~m)\\~~~&=& 0.695~m/s$

8 0

3 years ago

What is the atomic number of this element?

Zina [86]

The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon

So I believe it’s 6 hope this helps if not reply back

5 0

3 years ago

Read 2 more answers

A Car with drives into a solid object with 70 km/h, from which height would it fall if it was in free fall?

Ilya [14]

Answer:

18.9 m.

Explanation:

From the question given above, the following data were obtained:

Initial velocity (u) = 0 m/s

Final velocity (v) = 70 km/h

Height (h) =?

Next, we shall convert 70 km/h to m/s. This can be obtained as follow:

3.6 km/h = 1 m/s

Therefore,

70 km/h = 70 km/h × 1 m/s / 3.6 km/h

70 km/h = 19.44 m/s

Finally, we shall determine the height. This can be obtained as follow:

Initial velocity (u) = 0 m/s

Final velocity (v) = 19.44 m/s

Acceleration due to gravity (g) = 10 m/s²

Height (h) =?

v² = u² + 2gh

19.44² = 0² + (2 × 10 × h)

377.9136 = 0 + 20h

377.9136 = 20h

Divide both side by 20

h = 377.9136 / 20

h = 18.9 m

Thus, the car will fall from a height of 18.9 m

8 0

3 years ago

6) A map in a ship’s log gives directions to the location of a buried treasure. The starting location is an old oak tree. Accord

kiruha [24]

Answer:

Sorry cant find the answer but i hope you got it right and if you didn't you'll still do great. :)

Explanation:

4 0

3 years ago