Then the object moves in a circle.
Answer:
Cy and Di
Explanation:
We cannot tell exactly where the right end of the mirror is, but if we assume it is short of allowing Ed and Fred to see each other, we have the following:
Cy can see Cy and everyone to the right
Fred can see Di and everyone to the left
The only two that can see all of Cy, Di, Ed, and Fred are Cy and Di.
_____
If the mirror extends far enough to the right for Ed to see Fred, then all of Cy, Di, and Ed can see the four folks of interest.
Answer:
D.They are equal in magnitude and opposite in direction
Explanation:
- Newton's third law states that the action force is always associated with a reaction force.
- When a body 'A' exerts a force on body 'B', it is called the force of action.
- When the body 'B' in turn resist the force of 'A' is called the reaction force. It is the reactive force acted upon by the body 'B' on 'A'.
- This reaction force is equal in magnitude of the action force.
- If the two bodies remain in the same horizontal line, the 'A' exerts a force in the direction towards 'B' and the body 'B' exerts a reaction force in the direction towards 'A'.
- Hence, the two forces that are exerted by the bodies are equal in magnitude and opposite in direction.
Answer:
acceleration 8 km/h/s south
Explanation:
First of all, let's remind that a vector quantity is a quantity which has both a magnitude and a direction.
Based on this definition, we can already rule out the following two choices:
distance: 40 km
speed: 40 km/h
Since they only have magnitude, they are not vectors.
Then, the following option:
velocity: 5 km/h north
is wrong, because the car is moving south, not north.
So, the correct choice is
acceleration 8 km/h/s south
In fact, the acceleration can be calculated as

where
v = 40 km/h is the final velocity
u = 0 is the initial velocity
t = 5 s is the time
Substituting,

And since the sign is positive, the direction is the same as the velocity (south).