Answer: The answer is C.) 25 m/s^2.
Explanation: If you input 5 as s, you would have to use the exponent 2. This means that you have to multiply 5 by 5. 5 x 5= 25.
Edit: Also, because the surface is frictionless, it will make the object go faster too. Nothing can really slow it down unless something blocks it.
The mass attached to the spring must be 0.72 kg
Explanation:
The frequency of vibration of a spring-mass system is given by:
(1)
where
k is the spring constant
m is the mass attached to the spring
We can find the spring constant by using Hookes' law:
where
F is the force applied on the spring
x is the stretching of the spring
When a mass of m = 2.82 kg is applied to the spring, the force applied is the weight of the mass, so we have
and using 
and 
, we find
Now we want the frequency of vibration to be
f = 7.42 Hz
So we can rearrange eq.(1) to find the mass m that we need to attach to the spring:
#LearnwithBrainly
Answer:
An instrument for measuring the density of liquids.
Explanation:
A hydrometer is an instrument used to determine specific gravity. It operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats. Hydrometers can be divided into two general classes: liquids heavier than water and liquids lighter than water.
Thermohydrometers is one type of hydrometer.
Answer: O furo diminui enquanto a chapa aumenta a sua dimensão.
(The diameter decreases and the dimensions of the metal increases)
Explanation:
I will answer in English:
Here we have a piece of metal with a small hole on it, that is heated in a hoven.
We know that when a piece of metal is heated, it will expand (the density decreases, so the dimensions of the piece of metal increase).
Now, particularly, the hole will also expand but inwards, as each "extreme" of the piece of metal, will expand into where it has less resistance, so it will expand in the region where there is no material. This "inwards" expansion is why the diameter of the hole will decrease.
