D) because the refrigerator was much heavier than the other objects
Answer
given,
mass of the gate = 4.5 kg
distance between the hinge 1.5 m
mass of the bird = 1.1 kg
velocity of the bird = 5 m/s
a) from conservation of angular momentum
b) There is no external torque hence, momentum is conserved
initial kinetic energy =
initial kinetic energy =
= 13.75 J
final kinetic energy
KE =
KE =
KE = 7.14 J
Kinetic energy is not conserved
hence, the collision is inelastic.
Answer:
It tell you that the velocity is constant, what means that there's no acceleration
The answer to this is kilogram
Using lens equation;
1/o + 1/i = 1/f; where o = Object distance, i = image distance (normally negative), f = focal length (normally negative)
Substituting;
1/o + 1/-30 = 1/-43 => 1/o = -1/43 + 1/30 = 0.01 => o = 1/0.01 = 99.23 cm
Therefore, the object should be place 99.23 cm from the lens.