Answer:
1.5 m
Explanation:
Length. L = 12 m
Width, W = 16 m
Area, A = 12 x 16 = 192 m^2
Let the width of pavement be d.
The new length, L' = 12 + 2d
the new width, W' = 16 + 2d
New Area, A' = L' x W' = (12 + 2d)(16 + 2d) = 192 + 56 d + 4d^2
Difference in area = A' - A
285 = 192 + 56 d + 4d^2 - 192
93 = 56 d + 4d^2
4d^2 + 56 d - 93 = 0

\
d = 1.5 m
Thus, the width of the pavement is 1.5 m.
Answer:
The centripetal acceleration of the stone is 5 m/s²
Explanation:
The length of the string to which the stone is attached, r = 1 m
The speed with which the string is rotated, v = 5 m/s
The centripetal acceleration,
, is given as follows;

Therefore, the centripetal acceleration of the stone found as follows;

The centripetal acceleration of the stone,
= 5 m/s².
Answer:
Zero
Explanation:
Two long parallel wires each carry the same current I in the same direction. The magnetic field in wire 1 is given by :

Magnetic force acting in wire 2 due to 1 is given by :


Similarly, force acting in wire 1 is given by :
According to third law of motion, the force acting in wire 1 will be in opposite direction to wire 2 as :

So, the total magnetic field at the point P midway between the wires is in what direction will be zero as the the direction of forces are in opposite direction.