Answer:External forces are forces caused by external agent outside of the system. Internal forces are forces exchanged by the objects in the system.
Explanation:or our purposes, we will simply say that external forces include the applied force, normal force, tension force, friction force, and air resistance force. And for our purposes, the internal forces include the gravity forces, magnetic force, electrical force, and spring force.HOPE THIS HELPS!!! ^w^
Answer:
The kinetic energy of the cell phone is 9J
Explanation:
The kinetic energy is the energy possessed by a body by virtue of motion.
The kinetic energy is expressed as
KE= 1/2m(v)²
Given data
Mass of cell phone m= 80g--to kg=80/1000= 0.08kg
Velocity of cell phone v= 15m/s
Substituting our given data we have
KE= 1/2*0.08(15)²
KE= (0.08*225)/2
KE=18/2
KE= 9J
The answer is B. Bacteria in the plant nodules convert nitrogen from the soil into molecules the plants can use.
Answer:
Ek= 35.392 kJ or 35.392 10³ J
Explanation:
Formula for Kinetic energy:
Ek=
× m × ![v^{2}](https://tex.z-dn.net/?f=v%5E%7B2%7D)
since m= 65kg and v= 33m/s
Ek=
× 65×![33^{2}](https://tex.z-dn.net/?f=33%5E%7B2%7D)
Ek= 35.392 kJ or 35.392 10³ J
Answer:
The height from which the ball was thrown is 18.82 m
Explanation:
Given;
horizontal velocity of the ball, vi = 27.0 m/s
horizontal distance of the ball, d = 53.0 m
Apply kinematic equation, to determine the time taken for the ball to make a horizontal distance of 53.0 m.
d = vt
t = d/v
t = 53/27
t = 1.96 seconds
This time is equal to the time the ball spent in air before hitting the ground.
The vertical distance at this time, is the height from which the ball was thrown, and it is calculated as;
h = vt + ¹/₂gt²
v is vertical velocity, = 0
g is acceleration due to gravity
h = ¹/₂ x 9.8 x (1.96)²
h = 18.82 m
Therefore, the height from which the ball was thrown is 18.82 m