Answer:
300W
Explanation:
from my years in middle school, i have learned the equation is energy =power*time is 300W
Answer:
The one with highest velocity
Explanation:
The momentum of an object is given by

where
m is the mass of the car
v is the velocity of the car
In this problem, we have two identical cars: identical means they have same mass, so

The momentum of car 1 is

while the momentum of car 2 is

By comparing the two expressions, we see that the car with greatest momentum is the one with highest velocity, since the mass is the same.
The graph shows the production of Fe.
You can see from the graph that it increases rapidly and then slowly increases.
The answer is (A).
Cheers.
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.

You can conclude that the force of static friction acting on the boxcar is equal to 200N while you're pushing on it.