Answer:
D
Explanation:
Remember that magnets only attract at different poles. If both poles are the same, they repel
Answer:
The force of the nail pushing in the opposite direction
Answer:
3.25 seconds
Explanation:
It is given that,
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :

Where
s is the height in feet
For the given condition, the equation becomes:

When it hits the ground, h = 0
i.e.

It is a quadratic equation, we find the value of t,
t = 3.25 seconds and t = -0.134 s
Neglecting negative value
Hence, for 3.25 seconds the baseball is in the air before it hits the ground.
Answer:
12N
Explanation:
when a force is applied to a body but still stays at rest or moves at a constant speed , the frictional force is equal to the force applied