A ball on a string moves in a vertical circle. When the ball is at its lowest point, the tension in the string is equal to the ball's weight. (i said true..?)

A small projectile is launched horizontally 1 m above the surface of a smooth, airless planet, with sufficient speed for orbit. A bus riding in a small hole in the projectile feels an apperant weight greater than its true weight (I said false)

All points on a rotating wheel have the same angular acceleration (I said true)

could someone please correct me if i'm wrong? one or more of these are wrong...

Not true. The ball's weight is mg + m*v^2/r

IF the projectile is in orbit, yes, false.

last is true.

Let's go through each statement and determine if your answers are correct or incorrect:

1. A ball on a string moves in a vertical circle. When the ball is at its lowest point, the tension in the string is equal to the ball's weight. (You said true)

Your answer is correct. When the ball is at its lowest point in the vertical circle, there are two forces acting on it: the tension in the string and its weight. At this point, the tension in the string is equal to the ball's weight to maintain equilibrium.

2. A small projectile is launched horizontally 1 m above the surface of a smooth, airless planet, with sufficient speed for orbit. A bus riding in a small hole in the projectile feels an apparent weight greater than its true weight. (You said false)

Your answer is correct. When a projectile is launched horizontally with sufficient speed for orbit, the object will experience weightlessness. This means that the bus riding in the small hole in the projectile will not feel an apparent weight greater than its true weight.

3. All points on a rotating wheel have the same angular acceleration. (You said true)

Your answer is incorrect. All points on a rotating wheel do not have the same angular acceleration. In fact, different points on a rotating wheel have different linear velocities and accelerations depending on their distance from the axis of rotation. The angular acceleration, which is the rate at which the angular velocity changes, is the same for all points on the wheel, assuming there are no external torques acting on it.

So, out of the three statements, you got two correct answers. Statement 3 is incorrect as all points on a rotating wheel do not have the same angular acceleration.

A ball on a string moves in a vertical circle. When the ball is at its lowest point, the tension in the string is equal to the ball's weight. (I said true)

This statement is correct. When the ball is at its lowest point in the vertical circle, the tension in the string must be equal to the sum of the ball's weight and the centripetal force required to keep it in circular motion.

A small projectile is launched horizontally 1 m above the surface of a smooth, airless planet, with sufficient speed for orbit. A bus riding in a small hole in the projectile feels an apparent weight greater than its true weight. (I said false)

This statement is incorrect. When a projectile is launched horizontally with sufficient speed for orbit, it essentially becomes a satellite. In this case, the passengers inside the bus would experience weightlessness or zero apparent weight.

All points on a rotating wheel have the same angular acceleration. (I said true)

This statement is incorrect. Different points on a rotating wheel have different linear velocities and therefore different accelerations. However, all points on a rotating wheel do have the same angular velocity if they are rigidly attached to the same rotating object.