We would have to use wind or another source
Answer:
1. Collision- the sudden, forceful coming together in direct contact of two bodies
2. Newton's third law of motion is<em> naturally applied to collisions between two objects</em>. In a collision between two objects, both objects experience forces that are equal in magnitude and opposite in direction.
3. Momentum is the product of a moving object's mass and velocity. When two objects collide the total momentum before the collision is equal to the total momentum after the collision
120 minutes=2 hours
20/2= 10mph
<u>Answer:</u>
2.39 kg
<u>Explanation:</u>
There is conservation of momentum here in this problem so we will use the following problem:

where the mass of the student
is 48.5 kg,
the mass of the skateboard
is
kg,
the initial speed of the student
is 4.25 m/s; and
the speed of the student and skateboard
is 4.05 m/s.
So substituting the given values in the above formula to get:





Therefore, the mass of the skateboard is 2.39 kg.