<span>v is perpendicular to both E and B and has a magnitude E/B</span>
Answer:

Therefore, highest point that the cannon ball reaches is 168.7m
Explanation:
the cannon is fired at an angle 30 o to the horizonatal with a speed of 155 m/s
highest point that the cannon ball reaches?

g = 9.8m/s2

Therefore, highest point that the cannon ball reaches is 168.7m
I think the 3rd one is the answer
Answer:
V=15.3 m/s
Explanation:
To solve this problem, we have to use the energy conservation theorem:

the elastic potencial energy is given by:

The work is defined as:

this work is negative because is opposite to the movement.
The gravitational potencial energy at 2.5 m aboves is given by:

the gravitational potential energy at the ground and the kinetic energy at the begining are 0.
