To find the kinetic energy . You have to use this equation : 1/2m(v^2) .
Answer:
Speed, v = 5 m/s
Explanation:
We have,
The length of the football field, l = 100 m
A person takes 20 seconds to run its length.
It is required to find the speed of the person with which he should run. The distance covered divided by time taken is called its velocity.

So, the speed of the person is 5 m/s.
Answer:
Er = 231.76 V/m, 27.23° to the left of E1
Explanation:
To find the resultant electric field, you can use the component method. Where you add the respective x-component and y-component of each vector:
E1:

E2:
Keep in mind that the x component of electric field E2 is directed to the left.

∑x: 
∑y: 
The magnitud of the resulting electric field can be found using pythagorean theorem. For the direction, we will use trigonometry.
or 27.23° to the left of E1.
Answer:b. Hydroelectric energy uses the energy from the sun, which is a renewable resource
Explanation: