Answer:
a
When 

b
When 
Explanation:
From the question we are told that
The radius is R
The current is I
The distance from the center
Ampere's law is mathematically represented as
![B[2 \pi r] = \mu_o * \frac{I r^2 }{R^2 }](https://tex.z-dn.net/?f=B%5B2%20%5Cpi%20r%5D%20%20%3D%20%20%5Cmu_o%20%20%2A%20%20%5Cfrac%7BI%20r%5E2%20%20%7D%7BR%5E2%20%7D)

When 
=> 
But when 
![B = [\frac{\mu_o * I }{ 2 \pi R^2} ]* r](https://tex.z-dn.net/?f=B%20%3D%20%20%5B%5Cfrac%7B%5Cmu_o%20%2A%20%20I%20%7D%7B%202%20%5Cpi%20R%5E2%7D%20%5D%2A%20r)
Linear momentum is the product of mass and velocity. In this case, it is simply:
Answer:

Explanation:
= Force on one side of the door by first waiter = 257 N
= Force on other side of the door by second waiter
= distance of first force by first waiter from hinge = 0.567 m
= distance of second force by second waiter from hinge = 0.529 m
Since the door does not move. hence the door is in equilibrium
Using equilibrium of torque by force applied by each waiter

Answer:
After 4 s of passing through the intersection, the train travels with 57.6 m/s
Solution:
As per the question:
Suppose the distance to the south of the crossing watching the east bound train be x = 70 m
Also, the east bound travels as a function of time and can be given as:
y(t) = 60t
Now,
To calculate the speed, z(t) of the train as it passes through the intersection:
Since, the road cross at right angles, thus by Pythagoras theorem:


Now, differentiate the above eqn w.r.t 't':


For t = 4 s:
