The air inside becomes warmer, and that makes it LESS DENSE.
Less-dense air FLOATS in denser air. Since it's inside the balloon, it picks the balloon up when it floats.
Answer:
Increase
Explanation:
The plane strain fracture toughness of a metal is expected to increase with rising temperature.
Answer:
The block's mass should be 
Explanation:
Given:
Cart with mass 
From the conservation of energy before mass is added,

Where
amplitude of spring mass system,
spring constant

Now new mass
is added to the system,


Here, given in question frequency is reduced to half so we can write,

Where
frequency of system before mass is added,
frequency of system after mass is added.




Therefore, the block's mass should be 
True : yes there are planets in the universe without a parent star called
rogue planets.
False : most stars are not binary
What is rogue planets ?
planets which do not orbits the planetary system is known as roque planets. For example, pluto. Rogue planets can be smaller and bigger than jupiter too.
Free-floating planets or rogue planets without orbits around stars may also harbor life, some scientists believe. Due to the gravitational effects of giant planets within their system, these planets get kicked out of their system like any other planets formed around stars.
no most stars are not binary, binary which means two stars orbit around the common center and approximately only 40 binary stars have been found till not in our solar system.
Read more about solar system at:
brainly.com/question/12075871
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