PHYSICS
COLLEGE

Answer:

Explanation:

It is given that, a mass attached to a spring oscillates and completes 53 full cycles in 28 s. Frequency of the system is given by the number of oscillations or vibrations per second. Here, the frequency of this system is given by :

f = 1.89 Hertz

The relationship between the frequency and the time period of the spring is inverse i.e.

T = 0.52 seconds

Hence, this is the required solution.

COLLEGE

A bearing uses SAE 30 oil with a viscosity of 0.1 N·s/m2. The bearing is 30 mm in diameter, and the gap between the shaft and the casing is 2.0 mm. The bearing has a length of 3 cm. The shaft turns at ω = 350 rad/s. Assuming that the flow between the shaft and the casing is a Couette flow, find the torque required to turn the bearing.

Answer:

T = 2.78 x 10⁻³ N.m

Explanation:

given,

μ = 0.1 N.s/m²

diameter = 30 mm = 0.03 m

d y = 2 mm = 0.002 m

L = 0.03 m

ω = 350 rad/s

u = r ω

u = 0.015 x 350 = 5.25 N/s

τ = 262.5 N/m²

torque

T = τ A r

T = 262.5 x π r² x r

T = 262.5 x π x 0.015³

T = 2.78 x 10⁻³ N.m

MIDDLE SCHOOL

A group of organisms that is able to interbreed is called a a. kingdom

b. family

c. class

d. species

Answer:

D species

Explanation:

According to the most widely used species definition, the biological species concept, a species is a group of organisms that can potentially interbreed, or mate, with one another to produce viable, fertile offspring. In this definition, members of the same species must have the potential to interbreed.

HIGH SCHOOL

Which statement describe velocity and acceleration

What are the choice?

COLLEGE

Identify forces between two objects which are inversely proportional to the square of the distance between them. i. nuclear force between two neutrons; ii. gravitation force btween two celestial bodies; iii. electrostatic force between two electrons. 1. i and ii only 2. ii only 3. none is true. 4. iii only 5. i only 6. all are true. 7. i and iii only 8. ii and iii only

The force between two celestial bodies is a Newtonian gravitational force.

It is also called Newton's law of universal gravitation. We can write it down mathematically in the following way:

We can see from this formula that gravitational force is inversely proportional to the square of the distance between bodies.

The electrostatic force between two charges is Coulombs force. We can write it down like this:

This force is also inversely proportional to the square of the distance between interacting particles.

The nuclear force is a little bit more complicated. It can be expressed using the so-called Yukawa potential, which has the following form:

This interaction does not follow the inverse-square law.

The final answer should be 8.

It is also called Newton's law of universal gravitation. We can write it down mathematically in the following way:

We can see from this formula that gravitational force is inversely proportional to the square of the distance between bodies.

The electrostatic force between two charges is Coulombs force. We can write it down like this:

This force is also inversely proportional to the square of the distance between interacting particles.

The nuclear force is a little bit more complicated. It can be expressed using the so-called Yukawa potential, which has the following form:

This interaction does not follow the inverse-square law.

The final answer should be 8.