Answer:
r= 2.17 m
Explanation:
Conceptual Analysis:
The electric field at a distance r from a charge line of infinite length and constant charge per unit length is calculated as follows:
E= 2k*(λ/r) Formula (1)
Where:
E: electric field .( N/C)
k: Coulomb electric constant. (N*m²/C²)
λ: linear charge density. (C/m)
r : distance from the charge line to the surface where E calculates (m)
Known data
E= 2.9 N/C
λ = 3.5*10⁻¹⁰ C/m
k= 8.99 *10⁹ N*m²/C²
Problem development
We replace data in the formula (1):
E= 2*k*(λ/r)
2.9= 2*8.99 *10⁹*(3.5*10⁻¹⁰/r)
r =( 2*8.99 *10⁹*3.5*10⁻¹⁰) / (2.9)
r= 2.17 m
Answer:
46.4 s
Explanation:
5 minutes = 60 * 5 = 300 seconds
Let g = 9.8 m/s2. And 
be the slope of the road, s be the distance of the road, a be the acceleration generated by Rob, 3a/4 is the acceleration generated by Jim . Both of their motions are subjected to parallel component of the gravitational acceleration 
Rob equation of motion can be modeled as s = a_Rt_R^2/2 = a300^2/2 = 45000a[/tex]
Jim equation of motion is 
As both of them cover the same distance
So Jim should start 346.4 – 300 = 46.4 seconds earlier than Rob in other to reach the end at the same time
<em>projectile can only follow the straight line path when it is launched upward straightly so the correct option is <u>90 degree with respect to horizontal x -axis ..:)</u></em>
34.0 N which is the force that applied to the person by rowboat.
