A box is placed on rough surface.it has a normal force of magnitude 120N.a force of 20N applied to the right cannot move the box.calculate the magnitude and direction of the friction forces
Ff =UsN
Ff=(120)(20)
Ff=2400N
A.K.A. Newtons third law of motion.
If the box cannot move but has a force applied to the right, the force of the friction must be the exact same force but in the opposite direction.
Well, it seems like this box is having a case of the "I-don't-feel-like-moving" syndrome. Let's break it down:
The normal force acting on the box is 120N. This force is perpendicular to the surface and counters the weight of the box.
Since the applied force of 20N to the right isn't enough to overcome the friction and move the box, we can conclude that the magnitude of the frictional force must be greater than 20N. Otherwise, the box would simply slide away.
To determine the magnitude of the frictional force, we need to consider the equations of motion. If the box isn't moving, it means that the force of friction is equal in magnitude but opposite in direction to the applied force.
Therefore, the magnitude of the frictional force is also 20N, acting to the left. This force counters the applied force and keeps the box at rest.
So, the magnitude of the frictional force is 20N, and it acts to the left (opposite to the applied force).
Keep in mind that the direction of the frictional force will always oppose the motion or attempted motion of the box. It's like the surface saying, "Hey, not so fast! You stay right there!"
To calculate the magnitude and direction of the friction force acting on the box, we need to consider the forces acting on the box and the conditions necessary for it to be in equilibrium.
At first, let's analyze the forces acting on the box:
1. Normal Force (N): This is the force exerted by the rough surface on the box perpendicular to the surface. Given: N = 120 N.
2. Applied Force (F_applied): This is the external force applied to the box in the horizontal direction. Given: F_applied = 20 N.
Now, we can determine the friction force. In order for the box to be in equilibrium and not move, the force of friction must be equal in magnitude but opposite in direction to the applied force. Therefore, the magnitude of the friction force (F_friction) is 20 N, opposing the applied force.
If the box is not moving, this means the applied force is balanced by the force of static friction. Hence, the magnitude of the friction force (F_friction) = 20 N.
To summarize, the magnitude of the friction force acting on the box is 20 N.
Additionally, since the applied force is directed to the right, the friction force will be directed to the left (opposing the applied force).
In conclusion, the magnitude of the friction force is 20 N, and its direction is towards the left.