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:
Here is the complete question:
https://www.chegg.com/homework-help/questions-and-answers/magnetic-field-372-t-achieved-mit-francis-bitter-national-magnetic-laboratory-find-current-q900632
a) Current for long straight wire 
b) Current at the center of the circular coil 
c) Current near the center of a solenoid 
Explanation:
⇒ Magnetic Field due to long straight wire is given by (B),where 
Plugging the values,
Conversion 
,and 
⇒Magnetic Field at the center due to circular coil (at center) is given by,
So 
⇒Magnetic field due to the long solenoid,
Then 
So the value of current are 
,
and respectively.
Answer:
0.686 g of ice melts each second.
Solution:
As per the question:
Cross-sectional Area of the Copper Rod, A = 
Length of the rod, L = 19.6 cm = 0.196 m
Thermal conductivity of Copper, K = 
Conduction of heat from the rod per second is given by:
where
= temperature difference between the two ends of the rod.
Thus
Now,
To calculate the mass, M of the ice melted per sec:
where
= Latent heat of fusion of water = 333 kJ/kg
