Either no force at all, or else a group of forces whose vector sum is zero ...
often known as a 'balanced' group of forces.
You should be on the moving object
No
When the object is at rest, the acceleration is zero. so the net total force acting on the body from all directions should be zero. when the object is moving with constant velocity, the acceleration is zero, so in this case too, after the motion is started, the force on the body should be zero. when the velocity is increasing, some acceleration is present, so some force should be present in the direction of the motion. These are the various cases which can be explained by the equation: Force = Mass * Acceleration. here the mass remains constant, so acceleration depends on the net force
If your reference point it moving, then it cannot be considered a reference point. Your reference point should be something constant. Something that can be relative to any situation. If it moves, you lose this relativity.
Relative to the bus, you are moving towards the back. If your walking speed is slower than the speed of the moving bus (which it usually will be) then your motion relative to a point on the ground will be moving in the direction of the moving bus, but slower by the speed at which you are walking.
Either no force at all, or else a group of forces whose vector sum is zero ... often known as a 'balanced' group of forces.
Straight up in the air. It's already moving at your speed, so it's horizontal velocity will remain constant. Vertical motion and horizontal motion don't affect each other.
Assuming the graph is for displacement versus time, the motion should be constant velocity. If velocity versus time motion is constant acceleration
If the sum of all forces on an object is zero, then the object remains in constant, uniform motion. 'Constant uniform motion' means motion in a straight line at a constant speed. The physical description of such motion is "constant velocity". "Rest" is just constant velocity with a speed of zero. If the sum of all forces on an object is NOT zero, then the object's velocity must change. The change may consist of speeding up, slowing down, or turning in a different direction. Note: If you can, you should try and find the question in writing, so you can see what it's really asking.
I wonder what is the constant speed of this moving car
It means you should continue to progress.
When the object is at rest, the acceleration is zero. so the net total force acting on the body from all directions should be zero. when the object is moving with constant velocity, the acceleration is zero, so in this case too, after the motion is started, the force on the body should be zero. when the velocity is increasing, some acceleration is present, so some force should be present in the direction of the motion. These are the various cases which can be explained by the equation: Force = Mass * Acceleration. here the mass remains constant, so acceleration depends on the net force/
You should be on the moving object
The condition for an object to stay at rest or if moving, moving at a constant velocity is that the sum of forces acting on the object be zero or that no force acts on the object.
It should be moving forwards or backwards.
The reference point should be stationary, or not moving.
The reference point should be stationary, or not moving.