Question

multiple select question
select all that apply
which statements about equilibrium are accurate?
a skydiver descending at constant velocity under her parachute is in a state of equilibrium.
newtons first law identifies a net force as something that disturbs a state of equilibrium.
for a system to be in a state of equilibrium, it must have zero velocity and zero acceleration.
for a system to be in a state of equilibrium, there must be no forces exerted on it by the external world.
need help? review these concept resources.

Explanation:

• For the skydiver statement: When a skydiver is descending at a constant velocity under her parachute, according to Newton's first law (\(F_{net}=ma\), and since \(a = 0\) when \(v=constant\)), \(F_{net}=0\). So, she is in a state of equilibrium.
• For the Newton's first - law statement: Newton's first law (\(F_{net} = ma\)) states that if \(F_{net}

eq0\) (\(a
eq0\)), the state of motion (equilibrium, which implies \(a = 0\)) is disturbed.

• For the system - equilibrium - velocity - acceleration statement: In equilibrium, from \(F_{net}=ma\), if \(F_{net} = 0\), then \(a=0\). And if \(a = 0\), \(v\) is constant (it can be \(v = 0\) or \(v=\text{non - zero constant}\)).
• For the system - equilibrium - external - force statement: In equilibrium, \(F_{net}=\sum F_{external}=0\), not that there are no external forces. There can be external forces, but their vector sum is zero.

Answer:

A skydiver descending at a constant velocity under her parachute is in a state of equilibrium. ; Newton's first law identifies a net force as something that disturbs a state of equilibrium. ; For a system to be in a state of equilibrium, it must have zero velocity and zero acceleration.