A car is driving on a level highway. It is acted upon by the following forces: a downward gravitational force of 12 kN, an upward contact force due to the road of 12 kN, another contact force due to the road of 7 kN directed West, and a drag force due to air resistance of 5 kN directed East. What is the net force acting on the car?
To find the net force acting on the car, we need to consider the forces acting in the horizontal direction.
Given:
Gravitational force = 12 kN (directed downward)
Upward contact force = 12 kN
Contact force due to the road (westward) = 7 kN
Drag force due to air resistance (eastward) = 5 kN
Horizontal forces:
Contact force due to the road (westward) = 7 kN
Drag force due to air resistance (eastward) = 5 kN
To find the net force, we need to subtract the eastward force from the westward force:
Net force = Contact force due to the road (westward) - Drag force due to air resistance (eastward)
Net force = 7 kN - 5 kN
Net force = 2 kN (directed west)
So, the net force acting on the car is 2 kN directed westward.
To find the net force acting on the car, you need to consider the vector sum of all the forces acting on it. Since forces are vectors, you need to take into account both their magnitudes and directions.
First, let's analyze the forces acting on the car:
1. Downward gravitational force of 12 kN (acting vertically downward): This force is pulling the car down.
2. Upward contact force due to the road of 12 kN (acting vertically upward): This force is provided by the road to counteract the gravitational force.
3. Another contact force due to the road of 7 kN directed West: This force is acting horizontally in the opposite direction to the car's motion.
4. Drag force due to air resistance of 5 kN directed East: This force is acting horizontally in the same direction as the car's motion.
Now, let's calculate the net force:
In the vertical direction, the gravitational force and the upward contact force are equal in magnitude but opposite in direction. Therefore, the net vertical force is zero.
In the horizontal direction, the 7 kN contact force directed West and the 5 kN drag force directed East form a force pair in opposite directions. To find the net force, we can subtract the magnitude of one force from the magnitude of the other, taking into account their directions:
Net force = Magnitude of 7 kN Westward force - Magnitude of 5 kN Eastward force
= 7 kN - 5 kN
= 2 kN
So, the net force acting on the car is 2 kN, directed to the West.