Answer:
transmission: the passing of a wave through an object
Explanation:
Running on sand requires 1.6 times more energy spent than running on hard surface, so the force applied by our foot on sand is less.
Answer:
The true course:
north of east
The ground speed of the plane: 96.68 m/s
Explanation:
Given:
= velocity of wind = 
= velocity of plane in still air = 
Assume:
= resultant velocity of the plane
= direction of the plane with the east
Since the resultant is the vector addition of all the vectors. So, the resultant velocity of the plane will be the vector sum of the wind velocity and the plane velocity in still air.

Let us find the direction of this resultant velocity with respect to east direction:

This means the the true course of the plane is in the direction of
north of east.
The ground speed will be the magnitude of the resultant velocity of the plane.

Hence, the ground speed of the plane is 96.68 km/h.
Answer:
The starting velocity for ball 1 is 1.00 meter/second. Its ending velocity is 0.25 meter/second.
The change in velocity for ball 1 is 0.25 – 1.00 = -0.75 meter/seconds
Usually nice weather , i dont know the answer to the second part