A dragster maintains a speedometer reading
of 100 km/h and passes through a curve with
a constant radius.
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
4. I, II, III and IV
Friction (or a banked road) also provides a centripetal (sideways) force to the tires.
That should also be mentioned, since they are talking about a car on a curve.
A dragster maintains a speedometer reading
of 100 km/h and passes through a curve with a constant radius.
Which statement is true?
1. The dragster rounded the curve at a
changing velocity of 100 km/h.
2. The dragster moved along a straight line
at a constant velocity of 100 km/h.
3. The dragster rounded the curve at a
changing speed of 100 km/h.
4. All are wrong.
5. The dragster rounded the curve at a con-
stant velocity of 100 km/h.
Submit your question separately, not as an add-on to another person's question.
To determine which forces act on the car, we need to consider the nature of the situation.
Given that the dragster is maintaining a constant speedometer reading of 100 km/h, we can infer that the car is not accelerating. This means that the net force acting on the car is zero, according to Newton's second law (F = ma, where F is the net force, m is the mass of the car, and a is the acceleration).
Let's examine each force listed and determine if they contribute to the net force being zero:
I) Air drag pushing back on the car: This force opposes the motion of the dragster, acting in the opposite direction to its velocity. Since the car is maintaining a constant speed, the net force from air drag must be balanced by other forces.
II) Gravity pulling down on the car: This force acts vertically downward and does not affect the motion of the car along the curved path. It contributes to the normal force exerted by the ground but does not contribute to the net force acting on the car.
III) The ground pushing up on the car: This force is the normal force exerted by the ground on the car. It acts perpendicular to the surface of the ground and is needed to balance the force of gravity acting on the car. The normal force does not contribute to the net force acting on the car.
IV) Friction pushing the wheels (and the car) forward: This force is essential for the car to maintain its forward motion along the curved path. It counteracts any tendency of the car to slide off the curved path due to inertia.
V) Friction pushing the wheels (and the car) back: This force is contrary to the forward motion of the car and would act to slow down or stop the car. Since the car is maintaining a constant speed, this force is not present.
Considering the forces mentioned above, we can conclude that the forces acting on the car are forces I (air drag pushing back on the car), III (the ground pushing up on the car), and IV (friction pushing the wheels forward). Therefore, the correct answer is option 1: I, III, and V.