1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
juin [17]
3 years ago
10

The atomic number of yttrium is 39. The atomic mass of one of its isotopes is 89. How many neutrons are in an atom of this isoto

pe?
Physics
1 answer:
gogolik [260]3 years ago
8 0
50. The atomic mass is essentially a tally of all of the atoms in the nucleus, since electrons are essentially negligible in mass.
You might be interested in
as you go above earths surface, the acceleration due to gravity will decrease. find the height, i meters, above the earths surfa
aleksklad [387]

Answer:

1.23×10⁸ m

Explanation:

Acceleration due to gravity is:

a = GM / r²

where G is the universal gravitational constant,

M is the mass of the planet,

and r is the distance from the center of the planet to the object.

When the object is on the surface of the Earth, a = g and r = R.

g = GM / R²

When the object is at height i above the surface, a = 1/410 g and r = i + R.

1/410 g = GM / (i + R)²

Divide the first equation by the second:

g / (1/410 g) = (GM / R²) / (GM / (i + R)²)

410 = (i + R)² / R²

410 R² = (i + R)²

410 R² = i² + 2iR + R²

0 = i² + 2iR − 409R²

Solve with quadratic formula:

i = [ -2R ± √((2R)² − 4(1)(-409R²)) ] / 2(1)

i = [ -2R ± √(1640R²) ] / 2

i = (-2R ± 2R√410) / 2

i = -R ± R√410

i = (-1 ± √410) R

Since i > 0:

i = (-1 + √410) R

R = 6.37×10⁶ m:

i ≈ 1.23×10⁸ m

8 0
3 years ago
A single polarizer will stop _____ of the incoming light.
True [87]
A single polarizer will stop 50% of the incoming light.
8 0
3 years ago
Read 2 more answers
I'm bored. ........................
NeX [460]

Answer:

Explanation:

hi

8 0
3 years ago
Read 2 more answers
The rocket is fired vertically and tracked by the radar station shown. When θ reaches 66°, other corresponding measurements give
Flauer [41]

Answer:

velocity = 1527.52 ft/s

Acceleration = 80.13 ft/s²

Explanation:

We are given;

Radius of rotation; r = 32,700 ft

Radial acceleration; a_r = r¨ = 85 ft/s²

Angular velocity; ω = θ˙˙ = 0.019 rad/s

Also, angle θ reaches 66°

So, velocity of the rocket for the given position will be;

v = rθ˙˙/cos θ

so, v = 32700 × 0.019/ cos 66

v = 1527.52 ft/s

Acceleration is given by the formula ;

a = a_r/sinθ

For the given position,

a_r = r¨ - r(θ˙˙)²

Thus,

a = (r¨ - r(θ˙˙)²)/sinθ

Plugging in the relevant values, we obtain;

a = (85 - 32700(0.019)²)/sin66

a = (85 - 11.8047)/0.9135

a = 80.13 ft/s²

4 0
3 years ago
3. What is electric current?<br> The flow of moving electrons<br><br> electrons that move one time
3241004551 [841]

Answer:

An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume. ... In electric circuits the charge carriers are often electrons moving through a wire.

7 0
3 years ago
Read 2 more answers
Other questions:
  • For a circuit shown in the figure, all quantities are accurate in 3 significant figures. What is the power dissipated in 2-ohm r
    12·1 answer
  • What is the energy (in electron volts) of a 50 ghz (1 gigahertz = 109 hz) microwave photon?
    10·1 answer
  • benzene c6h6 and toluene c6h5ch3 for ideal solutions. at 35c the vapor pressure of benzene is 160 torr and that of toluene is 50
    10·1 answer
  • Within the electron cloud there are different _______________ of electrons. A) types B) energy levels C) atomic masses D) electr
    6·2 answers
  • A small child gives a plastic frog a big push at the bottom of a slippery 2.0 meter long, 1.0 meter high ramp, starting it with
    14·1 answer
  • The temp of some water with a mass of 10.0 g and a specific heat of 4.2 changed from 25.0 ' C to 35.0 ' C. How much heat was abs
    5·2 answers
  • A Jaguar XK8 convertible has an eight-cylinder engine. At the beginning of its compression stroke, one of the cylinders contains
    9·1 answer
  • You serve a tennis ball from a height of 1.80 m above the ground. The ball leaves your racket with a velocity of 18.0 m/s at an
    11·1 answer
  • The 49-g arrow is launched so that it hits and embeds in a 1.45 kg block. The block hangs from strings. After the arrow joins th
    5·1 answer
  • Two workers are sliding 490 kg crate across the floor. One worker pushes forward on the crate with a force of 410 N while the ot
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!