Answer:
do you mean before we used fossil fuels? steam.before steam? fire was used for like ...125,000 years ago. we were not smart back then but we were smart enough.
Explanation:
Answer:
-14.2m/s
Explanation:
Given parameters:
Initial velocity of the ball = 25m/s
Time = 4s
Unknown:
Final velocity of the ball = ?
Solution:
To solve this problem, we use the expression below;
v = u - gt
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
t is the time
v = 25 - (9.8 x 4) = -14.2m/s
Answer:
C. The sum remains the same.
Explanation:
The sum of the kinetic and potential energy remains the same as the all rolls from point A to E.
We know this based on the law of conservation of energy that is in play within the system.
The law of conservation of energy states that "energy is neither created nor destroyed within a system but transformed from one form to another".
- At the top of the potential energy is maximum
- As the ball rolls down, the potential energy is converted to kinetic energy.
- Potential energy is due to the position of a body
- Kinetic energy is due to the the motion of the body
The answer is B.) I had this question.
To find the force we use the formula,
F = ma , where m is mass and a acceleration
Using the formula,
F = ma
F = 0.42 x 14.8
F = 6.216 N / 6.22 N
Hope you liked the answer !