Answer: 6117.58 J
Explanation: 
We know that W=Fd*cos(theta) where theta is the angle between the displacement and the force.
In this case, we are given that F=225 N, d=30 m, and theta=25 degrees. 
Plugging all this in we get
W=225*30*cos(25)=6117.58 J
 
        
             
        
        
        
The direction of an electric current is by convention the direction in which a positive charge would move. Thus, the current in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery. Electrons would actually move through the wires in the opposite direction.
        
             
        
        
        
Answer:
The runner's acceleration was 
Explanation:
<u>Constant Acceleration Motion</u>
It's a type of motion in which the velocity of an object changes by an equal amount in every equal period of time.
Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

Solving for a:

The runner speeds up from vo=5 m/s to vf=9 m/s in t=4 seconds, thus:


The runner's acceleration was 
 
        
             
        
        
        
Answer:
6 km/h
Explanation:
V avg = ∆x/∆t = 3km / 30 min ×(60min/1h) = 3 km× 2 /h = 6 km/h