T = tension force in the rope in upward direction
m = mass of the box attached at end of rope = 56 kg
W = weight of the box in downward direction due to gravity
a = acceleration of the box in upward direction = 5.10 m/s²
weight of the box is given as
W = mg
inserting the values
W = (56) (9.8)
W = 548.8 N
force equation for the motion of the box is given as
T - W = ma
inserting the values
T - 548.8 = (56) (5.10)
T = 834.4 N
m = Mass of the refrigerator to be moved to third floor = 136 kg
g = Acceleration due to gravity by earth on the refrigerator being moved = 9.8 m/s²
h = Height to which the refrigerator is moved = 8 m
W = Work done in lifting the object
Work done in lifting the object is same as the gravitational potential energy gained by the refrigerator. hence
Work done = Gravitation potential energy of refrigerator
W = m g h
inserting the values
W = (136) (9.8) (8)
W = 10662.4 J
The change in velocity from 30 m/s north to 40 m/s south is a change of 70 m/s south
When I see the word "which" at the beginning of your question,
I just KNOW that there's a list of choices printed right there
next to he part that you copied, and for some mysterious
reason, you decided not to let us see the choices.
Any flashlight, light bulb, laser, or spark ... like lightning ...
converts some electrical energy into some light energy.
Answer:
Usually the coefficient of friction remains unchanged
Explanation:
The coefficient of friction should in the majority of cases, remain constant no matter what your normal force is. When you apply a greater normal force, the frictional force increases, and your coefficient of friction stays the same. Here's another way to think about it: because the force of friction is equal to the normal force times the coefficient of friction, friction is increased when normal force is increased.
Plus, the coefficient of friction is a property of the materials being "rubbed", and this property usually does not depend on the normal force.
