Answer:
the total kinetic and potential energy of the ball is constant (mechanical energy remains the same)
Explanation:
As the ball falls, kinetic energy is increased in direct relation with the decrease in potential energy
ΔKE + ΔPE = 0
Velocity = displacement (distance)/time
v=80m/4s
v=20m/s
velocity = 20 meters per second
Answer:
A jet plane flying straight and at level at constant speed
Explanation:
The<em> inertial frame </em>of reference is a frame of reference in which all <em>Newton law is valid</em> ie Newton second law of motion and therefore newton first law of motion holds good. <em>The frame of reference does not accelerate.</em>
All the object that is in the frame of reference are at rest or moving with constant rectilinear motion with constant velocity unless acted upon by any force.
We do not feel the gravitational forces from objects other than the Earth because they are weak.
