Infared = used by police
gamma = short wavelength
radio = largest wavelength
visible = only ones we can see
First we need to find the acceleration of the skier on the rough patch of snow.
We are only concerned with the horizontal direction, since the skier is moving in this direction, so we can neglect forces that do not act in this direction. So we have only one horizontal force acting on the skier: the frictional force,

. For Newton's second law, the resultant of the forces acting on the skier must be equal to ma (mass per acceleration), so we can write:

Where the negative sign is due to the fact the friction is directed against the motion of the skier.
Simplifying and solving, we find the value of the acceleration:

Now we can use the following relationship to find the distance covered by the skier before stopping, S:

where

is the final speed of the skier and

is the initial speed. Substituting numbers, we find:
Answer:
The astronaut can throw the hammer in a direction away from the space station. While he is holding the hammer, the total momentum of the astronaut and hammer is 0 kg • m/s. According to the law of conservation of momentum, the total momentum after he throws the hammer must still be 0 kg • m/s. In order for momentum to be conserved, the astronaut will have to move in the opposite direction of the hammer, which will be toward the space station.
Explanation:
The frequency of a wave is the reciprocal of its period.
A period of 0.008 sec means a frequency of
1 / 0.008 sec = 125 per sec . (125 Hz)
Answer:
Explanation:
Acceleration
is expressed in the following formula:
Where:
is the final velocity of the projectile
is the initial velocity of the projectile
is the time
Solving:
This is the acceleration of the projectile