Answer:
The answer is
<h2>2560 J</h2>
Explanation:
The kinetic energy of an object given it's mass and velocity can be found by using the formula
where
m is the mass
v is the velocity
From the question
m = 80 kg
v = 8 m/s
The kinetic energy is
We have the final answer as
<h3>2560 J</h3>
Hope this helps you
Answer:
The acceleration of the skateboarder is 2.067 m/s²
Explanation:
Given;
initial velocity of the skateboarder, u = 0.8 m/s
final velocity of the skateboarder, v = 7 m/s
time of motion, t = 3 s
The acceleration of the skateboarder is given as;
Therefore, the acceleration of the skateboarder is 2.067 m/s²
Answer:
B) Kinetic energy increases, potential energy decreases
Explanation:
In a given system, when a body is at rest, v =0m/s, the kinetic energy is at zero while the potential energy is at maximum. However, when a body is in motion with a velocity = v, the potential energy is at zero while the kinetic energy is at maximum.
Before this happen, the a body at rest (P.E = max) is set on motion, the kinetic energy gradually increases till it converts all the potential energy in the system to kinetic energy and then reverses back when the body goes to rest again.
In this case, before the batter hits the ball, the kinetic energy was at zero while the potential energy was at maximum. However, when he hits the ball and sets it into motion with a velocity V, the potential energy converts to kinetic energy and moves the ball with that energy till it has expanded it and comes to rest.
Potential Energy → Kinetic Energy → Potential Energy.
That's how the system keeps changing.
The woman weighs 100N now.
Explanation:
Given:
F is given as 400N
one full additional earth radius formed
To Find:
Weight of the woman=?
Solution:
We know that gravitational force is inversely proportional to the square of radius.
where
is the gravitational force
is the radius square
So when radius is doubled, the force becomes one fourth of the original.
Therefore 
