why does a car nose up when accelerating and nose down when braking?
which will have the greater acceleration rolling down an incline- a bowling ball or a volleyball?
The bowling ball and the volleyball will have the same acceleration.
I'm not exactly sure about the car thing, but it's probably because the front meets the most air resistance, pushing it down while accelerating, and when it brakes, the air resistance in the front is reduced while inertia keeps the car's end flying forward... the reduced air resistance and forward motion of the car's end lifts the front. I don't know a more technical explanation, if my original is true!
I hope that helps, at least.
1)consider the the torque on the car caused by the rear wheels. Remember Newtons third law?
2) The volleyball will get to the bottom fastest.
A car's nose-up effect during acceleration and nose-down effect during braking can be attributed to the forces acting on the car's center of gravity. When a car accelerates, the weight of the vehicle shifts towards the back due to the force exerted by the engine. This causes the front of the car to rise, resulting in a nose-up effect. Conversely, when the car brakes, the weight shifts towards the front, causing the front end to dip, resulting in a nose-down effect.
Now, concerning the question about the greater acceleration when rolling down an incline, the acceleration depends mainly on the mass and shape of the objects. In this case, the acceleration of both the bowling ball and the volleyball will be the same.
According to Newton's second law of motion (F = ma), the acceleration of an object is directly proportional to the force applied to it and inversely proportional to its mass.
When rolling down an incline, the force pulling the objects downhill is gravity, which is the same for both objects. Since gravity affects all objects equally regardless of their mass, the acceleration caused by gravity will be the same for both the bowling ball and the volleyball.
However, it's important to note that factors like air resistance and rolling friction might affect the observed acceleration in real-world scenarios, which can lead to slightly different outcomes.