Answer:
(B) The speed is larger at A than at B.
Explanation:
Point B, the final point of the trajectory, has higher electric potential than point A, the initial point of the trajectory, so the electric potential energy of the charged particle increases, which means that its kinetic energy must be decreasing, thus the speed at B must be lower than the speed at A.
Answer:
40 N/m
Explanation:
F = -kx (This is the Hooke's Law equation)
F is the force the spring exerts = 8 N
-k = spring constant
x = displacement (The distance stretched past it's natural length) = 20cm
x needs to be in meters, and 20 cm is = to 0.2 meters
Finally:
8N = -k (0.2m)
-k = 8N / 0.2 m
k = -40 N/m
Answer:
No, not necessarily
Explanation:
If an object is moving with an acceleration that causes its speed to be reduced, there will be a moment in which it reaches v = 0, but this doesn't necessarily mean that the acceleration isn't acting anymore. If the object continues its movement with the same acceleration, it's velocity will become negative.
An example of an object that has zero velocity but non-zero acceleration:
If you throw an object in the air with a certain velocity, it will move vertically, reducing its velocity in a 9,8 
rate (which is the acceleration caused by gravity). At a certain point, the object will reach its maximum height, and will start to fall. In the exact moment that it reaches the maximum height, before it starts falling, its velocity is zero, but gravity is still acting on the object (this is the reason why it starts falling instead of just being stopped at that point). Therefore, at that point, the object has zero velocity but an acceleration of 9,8 .
La capoeira se desarrolló en Brasil, derivada de las tradiciones traídas a través del Océano Atlántico por africanos esclavizados y alimentadas por el ardiente deseo de libertad. Pronto se practicó ampliamente en las plantaciones como un medio para romper los lazos de la esclavitud, tanto física como mentalmente.
Answer:
Friction force on the bullet is 58.7 N opposite to its velocity
Explanation:
As we know that initial speed of the bullet is 55 m/s
after travelling into the sand bag by distance d = 1.34 m it comes to rest
so final speed
now we can use kinematics top find the acceleration of the bullet
so we have
now by Newton's II law we know that
so we have
