Answer:
Final distance from the origin: 10.82 km. the vector points as shown in the attached image.
Angle with respect to the east: 
Explanation:
Please refer to the attached image. The cyclist's trip is indicated with the green arrows (9 km to the north followed by 6 km to the east.
So his final position is at the tip of this last vector, and indicated by the orange vector drawn form the point where the trip starts to the cyclist's final location.
We observe that this orange vector is in fact the hypotenuse of a right angle triangle, and we can estimate the distance from the origin by the Pythagorean theorem:

Notice that this is NOT the actual number of km that the cyclist pedaled to reach the final point.
Now, to find the value of the angle
, we need to use trigonometry, and in particular the tangent function gives us the ratio between the side of the triangle "opposite" to the angle, divided the side "adjacent" to the angle:

Now we can find the value of the angle by using the arctan function:

That would be kinetic energy
<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.
Answer:
The acceleration of car is 6.67 m/s².
Explanation:
Given that,
Initial velocity = 30 m/s
Distance = 15 m
Final velocity = 10 m/s
Time = 3 sec
We need to calculate the acceleration
Using formula of acceleration




Negative sign shows the car is slowing down.
Hence, The acceleration of car is 6.67 m/s².