PHYSICS
COLLEGE

Answer:

Answer:

The angular speed of the merry-go-round after the boy leaves it is 2.25 rad/s.

Explanation:

Given that,

Mass of boy = 20 kg

Total moment of inertia = 120 kgm²

Radius = 2 m

Speed = 1.5 m/s

We need to calculate the moment of inertia of boy

Put the value into the formula

We need to calculate the

Using conservation of angular momentum

Put the value into the formula

Hence, The angular speed of the merry-go-round after the boy leaves it is 2.25 rad/s.

MIDDLE SCHOOL

Which of the following is the correct SI unit to use in measuring amount of material contained in a solid sphere? A. kilograms

B. tons

C. ounces

D. pounds

The correct SI unit to be used for measuring the amount of material in a solid sphere would be kilograms. Kilograms are officially the base unit of mass, and other measurements such as pounds in the imperial system are defined in terms of kilograms.

Correct answer is Kilograms

COLLEGE

When tuning his guitar, a music student notices that the string is not vibrating at the desired frequency of 120 Hz, so he tightens the string by 15.5% to get this frequency. At what frequency was the string vibrating when he first started the tuning process

Answer:

Explanation:

We know that

frequency ∝ √ Tension

So

Δn / n = 1/2 (ΔT / T)

Δn / n = .155 / 2 ( GIVEN )

= .0775

Δn = .0775 n

Let the original frequency be n

n +Δn = 120

n + .0775 n = 120

n = 111.36

HIGH SCHOOL

A homogenous mixture of two or more substances is known as a(n) element

compound

solution

atom

Wait homogenous would be solution. ;w they have to be different substances.

COLLEGE

The pressure 75.0 meters underwater is 837 kpa. what is this pressure in atm

Note that

1 atm = 101.325 kPa

The given pressure is

Answer: 8.26 atm (nearest hundredth)

1 atm = 101.325 kPa

The given pressure is

Answer: 8.26 atm (nearest hundredth)