Let
be the direction the swimmer must swim relative to east. Then her velocity relative to the water is

The current has velocity vector (relative to the Earth)

The swimmer's resultant velocity (her velocity relative to the Earth) is then


We want the resultant vector to be pointing straight north, which means its horizontal component must be 0:

which is approximately 41º west of north.
Answer:
44J
Explanation:
Given parameters:
Mass of rock = 0.22kg
Initial velocity = 20m/s
Distance moved = 10m
Unknown:
Initial kinetic energy of the rock = ?
Solution:
To solve this problem, we need to understand that kinetic energy is the energy due to the motion of a body.
It is mathematically expressed as;
Kinetic energy =
m v²
m is the mass
v is the velocity
Kinetic energy =
x 0.22 x 20² = 44J
If it is a multiple choice question is C. Infrared waves do not carry enough energy to kill cancerous cells.
Answer:
When a an object is been rotated its resistance capacity to that rotational force is know as rotational inertia and this mathematically given as

Where m is the mass
r is the rotation radius
For the spinning of the lamp as a baton to work the location of the center of mass of the floor lamp needs to be located
This is more likely to be located closer to base of the lamp as compared to the top, so success of spinning a floor lamp like a baton is highly likely if the lamp is grabbed closer to the base because that is where the position of its center of mass is likely to be.
Explanation: