A block of wood is placed on a surface. A force is applied parallel to the surface to move the body. The frictional force acts as ________
A. normal to the surface upwards
B. normal to the surface downwards
C. along the direction of the applied force
D. opposite to the direction of the applied force
Answer:D
A block of wood is placed on a surface. A force is applied parallel to the surface to move the body. The frictional force acts as ________
A. normal to the surface upwards B. normal to the surface downwards C. along the direction of the applied force D. opposite to the direction of the applied force