Answer:
Friction between the box and the floor is 25N to the left.
Explanation:
According to Newton's second law of motion, the net force acting on an object is equal to the produce between the object's mass and its acceleration:
where
m is the mass of the object
a is its acceleration
In this problem, we have two forces acting on the object:
- The applied force, F = 25 N, to the right
- The force of friction 
, opposing the motion of the box, so to the left
So we can write the net force as
Also, we know that the box is moving at constant speed: this means its acceleration is zero, so
Therefore
WHich means:
And therefore,
which means that the force of friction is also 25 N.
Answer:
If you know that that free fall acceleration g on the Moon is about 6 times less than on the Earth, it gives you the answer: on the Moon the same pendulum will have a period about √6≈2.45 longer than on the Earth.
C. Mechanical, because temperature can cause solid objects to expand and contract, causing rocks to split apart.
The car heads east at an average speed of 50 miles per hour from the intersection point towards East. The truck heads east at an average speed of 60 miles per hour from the intersection point towards South.
The distance of car from the intersection point after t hours is 
.
The distance of truck from the intersection point after t hours is 
.
Since these distances are perpendicular to each other, distance apart d (in miles) at the end of t hours is
Thus the distance apart is 
