As the box is moving with a constant velocity, the two forces acting on the box are canceling each other.
Then friction force = 80 Newtons but in the opposite direction.
Friction force = Mu * Normal force exerted by ground = Mu * weight of box
So we find Mu.
Mu = coefficient of friction between box and horizontal surface
= Force of friction / weight = 80 / 50 * 9.81 = 0.163
When an identical box is placed on top, the force of friction is
= Mu * total weight = 0.163 * (50+50) * 9.81 = 159.9 Newtons
Answer:
The centripetal acceleration of the stone is 5 m/s²
Explanation:
The length of the string to which the stone is attached, r = 1 m
The speed with which the string is rotated, v = 5 m/s
The centripetal acceleration, 
, is given as follows;
Therefore, the centripetal acceleration of the stone found as follows;
The centripetal acceleration of the stone, = 5 m/s².
Gravity and air resistance
i took the test and got 100%
This question is asking you to determine if individual atoms or systems, or both have these types of energy. A system would be "all the molecules or atoms" whereas an individual atom is "each of the molecules or atoms."
Answers:
A. All the molecules or atoms in motion have kinetic energy.
B. Each molecule or atom in motion has kinetic energy.
D. All the molecules or atoms in motion have thermal energy.
The only incorrect answer is C because individual atoms don't have thermal energy, only when they interact with other atoms. Still, atoms do have kinetic energy, which has the potential to turn into heat energy in these interactions.
Hope this helps!
