Answer:
(a)

(b) 

Explanation:
Let us take the north direction to be the positive y-axis and the east to be positive x-axis.
First day:
25.0 km southeast, which implies
south of east. The y-component will be negative and the x-component will be positive.


Second day:
She starts off at the stopping point of last day. This time, both the y- and x-components are positive.


Therefore, total displacements:


Magnitude of displacements,

Direction,

Given that,
Radius of track, r = 50 m
time , t = 9 s
velocity, v = ?
Distance covered by car in one lap around a track is equal to the circumference of the track.
C = 2 π r = 2 * 3.14 * 50
C = 314.159 m
Distance covered by car, s = 314.159 m
Velocity = distance/ time
V = 314.159 / 9
V = 34.9 m/s
The average velocity of car is 34.9 m/s.
The unit of measurement of work is the Joules. B.
A) Acceleration= (282m/s-0m/s)/5.0s= 56.4m/s^2
b) Deceleration=(0m/s-282m/s)/1.40s=201.4m/s^2 (here we reject negative because deceleration already take into account negative)
c) for the first one the multiple will be 5.76g
for the second one it will be 20.6g
Answer:
b) Gravity
Explanation:
Gravity acts all of the time, when you apply force to a projectile it has to be more than the forces of the gravity and air resistance together so the projectile can move, when the rock is at the top of its trajectory the force that you applied at the beginning is getting lost, so the other forces (air resistance and gravity) make the rock fall to the floor.