Answer:
A. The particle model, because only high-energy frequencies of light can remove electrons .
Explanation:
Each photon of blue light has higher energy than each photon of red light has . So when each photon strikes each electron , it gets ejected . But the photon of red light has not sufficient energy to eject electron . Once the photon of red light strikes the electron , the energy is wasted off . Energy of photon can not be accumulated . Thus photon behaves like particle .
The answer is C) A girl hangs by both hands, motionless, from a trapeze.
Answer:
5 kg
Explanation:
Acceleration = 6 m/s^2
Force = 30 N
Force = mass * acceleration
mass = force / acceleration
mass = 30 / 6
mass = 5 kg
Answer: 0.5
Explanation:
The modulus of elasticity (called <em>"alargamiento unitario"</em> in spanish) 
of a spring is given by the following formula:
Where:
is the original length of the spring
is the elongation of the spring, being 
the length of the spring after a force is applied to it.
Then:
Answer:
Solution is given in the attachments,below.
