PE is the energy acquired by a body due to its height ! While KE is the energy acquired by the body due to its motion !
KE+PE = mechanical energy and thus mechanical energy is always conserved due to the conservation of energy which states that energy is neither created nor destroyed but only transformed !
Answer:
a ) 2.68 m / s
b ) 1.47 m
Explanation:
The jumper will go down with acceleration as long as net force on it becomes zero . Net force of (mg - kx ) will act on it where kx is the restoring force acting in upward direction.
At the time of equilibrium
mg - kx = 0
x = mg / k
= (60 x 9.8 ) / 800
= 0.735 m
At this moment , let its velocity be equal to V
Applying conservation of energy
kinetic energy of jumper + elastic energy of cord = loss of potential energy of the jumper
1/2 m V² + 1/2 k x² = mg x
.5 x 60 x V² + .5 x 800 x .735 x .735 = 60 x 9.8 x .735
30 V² + 216.09 = 432.18
V = 2.68 m / s
b ) At lowest point , kinetic energy is zero and loss of potential energy will be equal to stored elastic energy.
1/2 k x² = mgx
x = 2 m g / k
= (2 x 60 x 9.8) / 800
= 1.47 m
Answer:
Due to the resistance of air, a drag force acts on a falling body (parachute) to slow down its motion. Without air resistance, or drag, objects would continue to increase speed until they hit the ground. The larger the object, the greater its air resistance. Parachutes use a large canopy to increase air resistance. Also, Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward. An upward net force on a downward falling object would cause that object to slow down. The skydiver thus slows down. Sorry if not helpful.
Answer:
The image result of an object reflected by a convex mirror is typically virtual, upright, and smaller. Discover how moving the object farther away from the mirror's surface affects the size of the virtual image formed behind the mirror
Explanation:
