Answer:

Explanation:
Regardless of the initial velocity of the pebble, the acceleration of the pebble is equal to the gravitational acceleration which is equal to 9.8 m/s2 towards downwards direction.
This can be shown by Newton's Second Law. According to the law, the net force applied on an object is equal to mass times acceleration of that object.
During the downward motion, the only force acting on the pebble is the gravitational force, hence its acceleration is equal to gravitational acceleration.
Experience research study. experiment explain scientific process useful for research for an action . Albert enistein . He was found all the scientific knowledge. more scientist same method
Potential energy = (mass) · (gravity) · (height)
PE = (60 kg) · (9.8 m/s²) · (10 m)
PE = (60 · 9.8 · 10) · (kg · m²/s² )
PE = 5,880 joules
Answer:
magnification is - 159
objective distance is 3.85 cm
Explanation:
Given data
focal length f1 = 1.40 cm
focal length f2 = 2.20 cm
separated d = 19.6 cm
to find out
angular magnification and How far from the objective
solution
we know magnification formula that is
magnification = ( - L / f1 ) (D/f2)
here D = 25 cm put all value
magnification = ( - 19.6 / 1.40 ) (25/2.20)
magnification = - 159
and
now we apply lens formula
i/f = 1/q + 1/p
p = f2 = 2.20
so
q = f2 p / p -f2
q = 1.4(2.20) / ( 2.2 - 1.4 )
q = 3.85 cm
so objective distance is 3.85 cm