Forces are balanced when net force on the object is zero or the sum of all force on the object is zero.
For book kept on a shelf, the weight of the book in down direction is balanced by the normal force on the book by the shelf. hence the book kept on a shelf is an example of balanced force.
In case of air rushing out of balloon , the balloon experience a net force by the air coming out of it.
rolling over and falling off the bed , the object falls under gravity force.
a car speeding up accelerates. since it accelerates , it has net force on it.
Answer:
It is used in MRI because it does not damage cells
Radio waves are used for space research because they have very long wavelengths
Explanation:
Many parts of the electromagnetic spectrum are applied in clinical diagnosis and treatment of illnesses. However, these highly ionizing radiation damage cells and its dosage must be carefully managed to avoid creating radiation related health problems for the patients.
Radio waves can be used in MRI without issues because the energy of the radiation is not sufficient to cause damage to cells but is sufficient to provide images for the sake of medical diagnosis.
Secondly, radio waves have long wavelength. This property is suitable for long range
communication. Hence it can be used in space research
Answer:

Explanation:
We can use the conservation of momentum. The initial momentum is equal to the final momentum:
x-coordinate

(1)
y-coordinate

(2)
We can divide equations (2) and (1):



I hope it helps you!
<span>For adults age 19–50, Dietary Guidelines recommend consuming at least 4 cups of vegetables and fruits daily. this means the answer is C</span>
Answer:
Explanation:
The displacement is the distnce of the shopper from the starting point.
Sum of movement along the vertical = 40-20 = 20m
Movement along the horizontal (x direction) = 15.0m
Displacement will be gotten using the pythagoras theorem.
d = √20²+ 15²
d = √400+225
d = √625
d = 25.0m
Hence the shoppers total displacement is 25.0m