I believe it's frequency.
Answer:

Explanation:
First ship starts at Noon with speed 20 Knots towards West
now we know that 2nd ship starts at 6 PM with speed 15 Knots towards North West
so after time "t" of 2nd ship motion the two ships positions are given as


now we can find the distance between two ships as

now we have


now we will differentiate it with respect to time

here we know that

so we have

now we have


We know that;
power=W/t
15000Watts=1800000J/t
t=1800000J/15000Watts
t=120s
Answer:
(B) 1.6 m/s^2
Explanation:
The equation of the forces acting on the box in the direction parallel to the slope is:
(1)
where
is the component of the weight parallel to the slope, with m = 6.0 kg being the mass of the box, g = 9.8 m/s^2 being the acceleration of gravity,
being the angle of the incline
is the frictional force, with
being the coefficient of kinetic friction, N being the normal reaction of the plane
a is the acceleration
The equation of the force along the direction perpendicular to the slope is

where
is the component of the weight in the direction perpendicular to the slope. Solving for N,

Substituting into (1), solving for a, we find the acceleration:
