The motor does 20 J of work on the block, it means that the total mechanical energy of the block has increased by 20 J. But the increase in total mechanical energy is equal to the sum of the increases in potential energy and kinetic energy:
So, if the gravitational potential energy has increased by 15 J, the kinetic energy has increased by
Answer:
Electrical energy spontaneously
Explanation:
Answer: a) It will take more time to return to the point from which it was released
Explanation: To determine how long it takes for the ball to return to the point of release and considering it is a free fall system, we can use the given formula:
, where:
d is the distance the ball go through;
v₀ is the initial velocity, which is this case is 0 because he releases the ball;
a is acceleration due to gravity;
t is the time necessary for the fall;
Suppose <em>h</em> is the height from where the ball was dropped.
On Earth:
h=0.t + 
h = 5t²
= 
On the other planet:
h = 0.t + 
h = 15.t²
= 
Comparing the 2 planets:
= 
or 
Comparing the two planets, on the massive planet, it will take more time to fall the height than on Earth. In consequence, it will take more time to return to the initial point, when it was released.
Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
