Answer:
The angle between the electric field lines and the equipotential surface is 90 degree.
Explanation:
The equipotential surfaces are the surface on which the electric potential is same. The work done in moving a charge from one point to another on an equipotential surface is always zero.
The electric field lines are always perpendicular to the equipotential surface.
As

For equipotential surface, dV = 0 so

The dot product of two non zero vectors is zero, if they are perpendicular to each other.
Answer:
v = 54 m/s
Explanation:
Given,
The maximum height of the flight of golf ball, h = 150 m
The velocity at height h, u = 0
The velocity of the golf ball right before it hits the ground, v = ?
Using the III equations of motion
<em> v² = u² + 2gh</em>
Substituting the given values in the above equation,
v² = 0 + 2 x 9.8 x 150 m
= 2940
v = 54 m/s
Hence, the speed of the golf ball right before it hits the ground, v = 54 m/s
Answer:
Explanation:
1 mile=5280 ft
1 hour=3600 seconds
Changing speed from mi/h to ft/s

Time of flight, 
From fundamental kinematics equations
where g is acceleration due to gravity whose value is taken as 32.2 ft/s2 and h is the distance
By substitution

Answer:
19.1 secs
Explanation:
The first step is to calculate the velocity
= 17.4/47.6
= 0.37 m/s
Therefore the time taken for the person to reach the top can be calculated as follows
= 17.4/(0.37+0.541)
= 17.4 / 0.911
= 19.1 secs
Hence the time taken is 19.1 secs