The first, fourth and sixth options. A person walks up a flight of stairs, wind lifts a balloon into the air, and a weightlifter holds a barbell straight overhead.
Answer:
Diffraction
Explanation:
Diffraction is the bending of waves around obstacles and openings. The amount of diffraction increases with increasing wavelength.
Answer:
Height above a surface
Explanation:
Gravitational potential energy is the energy which an object possesses due to its position above a surface.
It is also the amount of work a force has to do in order to bring an object from a particular position to a point of reference.
It is given mathematically as:
P. E. = m*g*h
where m = mass of the body
g = acceleration due to gravity
h = height above a surface
m*g represents the weight of the object.
Hence, Gravitational potential energy is the product of an object's weight and its height above a surface/reference point.
