The kinetic energy of an object is directly proportional to its mass, and to the square of its velocity.
Muscles function only by contracting. This makes it necessary for one end of the muscle to be fixed and the other mobile.
Take the bicep for example.
Its origin is at the shoulder and its two heads connect to the bones of the forearm, the radius and ulna.
Now, had the muscle not been fixed at one end, and contracted, it would pull both our shoulder and forearm together resulting in an ineffective movement. The desired motion is to lift the forearm (proximal and distal movement) which can only be achieved if the bicep is fixed at the shoulder and allowed to move at the forearm.
Answer:
25 m/s
Explanation:
This question can be solved using equation of motion

where
v is the final velocity
u is the initial velocity
s is the distance covered while moving from initial to final velocity
a is the acceleration
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Given
box moved for distance of 62.5 m
Friction slows the box at –5.0 m/s2----> this statement means that there is deceleration , speed of truck decreases by 5 m/s in every second until the box comes to rest. Friction causes this deceleration.
thus in this problem
a = -5.0 m/s2
V = 0 as body came to rest due to friction deceleration
u the initial velocity we have to find
the initial velocity of box will be the same as speed of truck, as the box was in the truck and hence box will pick the speed of truck.
so if we find speed of box, we will be able get sped of truck as well.
using equation of motion

Thus, initial speed with the truck was travelling was 25 m/s.
Answer:
When two objects interact, each one exerts a force on the other that can cause energy to be transferred to or from the object. For example, when energy is transferred to an Earth-object system as an object is raised, the gravitational field energy of the system increases. This energy is released as the object falls; the mechanism of this release is the gravitational force. Likewise, two magnetic and electrically charged objects interacting at a distance exert forces on each other that can transfer energy between the interacting objects.
Explanation:
Even when an object is sitting still, it has energy stored inside that can be turned into kinetic energy (motion). ... A force is a push or pull that causes an object to move, change direction, change speed, or stop. Without a force, an object that is moving will continue to move and an object at rest will remain at rest.
Explanation:
physical exertion.
lack of physical activity.
lack of sleep.
being overweight or obese.
periods of emotional stress.
boredom.
grief.
taking certain medications, such as antidepressants or sedatives.