You are driving a car down a straight road at a constant 48 miles per hour.
Consider the following forces:
I) air drag pushing back on the car;
II) gravity pulling down on the car;
III) the ground pushing up on the car;
IV) friction pushing the wheels (and the car)
forward; and
V) friction pushing the wheels (and the car)
back.
Which force(s) act on the car?
1. I, III and V
2. I, II and III
3. II, III and IV
4. I, II, III and IV
5. I and II
The answer is I,II,III,IV trust me.
5. l, ll, lll, and lV
The forces that act on the car are:
1. I) air drag pushing back on the car
2. III) the ground pushing up on the car
3. IV) friction pushing the wheels (and the car) forward
Therefore, the correct answer is: 1. I, III and IV
To determine which force(s) act on the car, let's go through each force and analyze its effect on the car:
I) Air drag pushing back on the car: Air drag is a force opposing the motion of the car caused by air resistance. It acts in the opposite direction of the car's velocity and tries to slow it down. This force is always present when the car is moving, so it acts on the car.
II) Gravity pulling down on the car: Gravity is the force by which a planet or other body draws objects toward its center. It acts vertically downward and is always present. It is responsible for the weight of the car. Hence, gravity acts on the car.
III) The ground pushing up on the car: The ground exerts a normal force perpendicular to its surface. When the car is on the ground, the ground pushes up on the car to balance the downward force of gravity. This force is necessary to prevent the car from sinking into the ground. Therefore, the ground pushes up on the car.
IV) Friction pushing the wheels (and the car) forward: Friction is the force that opposes the relative motion between two surfaces in contact. In this case, as the wheels rotate and push the car forward, a static friction force acts in the forward direction to allow the car to move. This force enables the car to overcome inertia and move forward. So, friction pushes the wheels (and the car) forward.
V) Friction pushing the wheels (and the car) back: This force is not applicable in this scenario since there is no backward force acting on the car.
Based on the analysis, the forces that act on the car are: I) air drag pushing back on the car, III) the ground pushing up on the car, and IV) friction pushing the wheels (and the car) forward.
Therefore, the correct answer is 1. I, III, and V.