Newton's first law of motion.
Answer:
a) Em= K +U, b) Em= K
Explanation:
The system in this case is formed by the mobilizes and the hill.
Let's write the expressions correctly and completely.
a) When the car moves in the path, the mechanical energy is the siua of the kinetic energy of the car and the potential energy of the car when going up the hill.
Em = K + U
be) when the car moves in the flat part all the mechanical energy is formed by its kinetic energy that is calculated with the mass and speed of the car
Em = K
c) When the car goes up the hill the energy the mechanical energy is conserved, but part of the kinetic energy is transformed into potential energy.
Answer:
(a) 32.5 kgm/s
(b) 32.5 Ns
(c) 10.8 N
Explanation:
The change in momentum can be calculated from the definition of linear momentum:
Then, the change in momentum of the body is of 32.5 kgm/s (a).
Now, from the impulse-momentum theorem, we know that the change in momentum of a body 
is equal to the impulse 
exerted to it. So, the impulse produced by the force equals 32.5 kgm/s (or 32.5 Ns) (b).
Finally, since we know the value of the impulse and the interval of time, we can easily solve for the magnitude of the force:
It means that the magnitude of the force is of 10.8N (c).
Answer:
11.6km
4.4km in the negative direction
Explanation:
Distance is the total length of path covered and traveled by a body.
So, for this car on a straight line;
Total distance = 8km + 3.6km = 11.6km
Displacement is the distance traveled along a path and the direction it takes.
It is a vector quantity with magnitude and directional attributes.
For this journey;
Displacement = 8km - 3.6km = 4.4km in the negative direction.
