A boy throws a stone straight upward with an initial
1 answer:
You might be interested in
The final kinetic energy of the ball is 2.45 J
Explanation:
We can solve this problem by using the law of conservation of energy.
In absence of frictional effect, the mechanical energy of the apple must be conserved during the fall. So we can write:
where :
is the initial potential energy, at the top
is the initial kinetic energy, at the top
is the final potential energy, at the bottom
is the final kinetic energy, at the bottom
By explicing the potential energy, we can rewrite the equation as:
where:
m = 0.5 kg is the mass of the apple
is the acceleration of gravity
is the initial height
is the final height
The initial kinetic energy is zero, since the ball starts from rest:
Therefore we can solve the equation for , the final kinetic energy of the ball:
Learn more about kinetic energy and potential energy:
#LearnwithBrainly
The average speed is 20.8 m/s
Explanation:
The average speed for the trip is given by:
where
d is the distance covered
t is the time elapsed
For the trip in this problem, we have:
d = 187 km = 187,000 m is the distance travelled
The initial time is 10:00 pm while the arriving time is 12:30 am: this means that the time elapsed is 2.5 hours. Converting into seconds,
Therefore, the average speed for the trip is
Learn more about average speed:
#LearnwithBrainly