Answer:
0.102 m
Explanation:
k = spring constant of the spring = 125 N/m
m = mass of the block attached to the spring = 650 g = 0.650 kg
x = maximum extension of the spring
h = height dropped by the block = x
Using conservation of energy
Spring potential energy gained = Gravitational potential energy lost
(0.5) k x² = mgh
(0.5) k x² = mgx
(0.5) (125) x = (0.650) (9.8)
x = 0.102 m
Answer:
0.125 cm
Explanation:
1/f = 1/d¡ + 1/d。
Find the focal point
(13.0^-1 + 20.8^-1) = 0.125 m
Focal point = 0.125 m
m = Mass of the refrigerator to be moved to third floor = 136 kg
g = Acceleration due to gravity by earth on the refrigerator being moved = 9.8 m/s²
h = Height to which the refrigerator is moved = 8 m
W = Work done in lifting the object
Work done in lifting the object is same as the gravitational potential energy gained by the refrigerator. hence
Work done = Gravitation potential energy of refrigerator
W = m g h
inserting the values
W = (136) (9.8) (8)
W = 10662.4 J
Pretty sure it’s A. Hope this helps.