In both cases an applied force of 100N accelerates block A which weighs 100N. In which case is this acceleration greater?

To determine which case has a greater acceleration, we need to compare the forces acting on block A in each case. The acceleration of an object is directly proportional to the net force acting on it, according to Newton's second law of motion (F = ma).

In both cases, an applied force of 100N is acting on block A, which weighs 100N. Therefore, the net force in both cases is also 100N. However, we need to consider other forces that might influence the acceleration.

Case 1: No other forces
If there are no other forces acting on block A, the net force is simply the applied force of 100N. In this case, the acceleration can be calculated using the formula F = ma, where F is the net force, m is the mass, and a is the acceleration. Since the mass of block A is 100N, the acceleration is:

F = ma
100N = 100N * a
a = 1 m/s^2

Case 2: Additional forces
If there are other forces acting on block A in addition to the applied force, the net force will be affected. If the additional forces oppose the motion, the net force will be smaller, resulting in a lower acceleration.

For example, if there is a frictional force acting opposite to the motion of block A, the net force will decrease. In this case, let's assume the net force becomes 80N. Using the same formula, we can calculate the acceleration:

F = ma
80N = 100N * a
a = 0.8 m/s^2

Comparing the two cases, we can see that the acceleration is greater in Case 1 (without any additional forces) since it has an acceleration of 1 m/s^2, whereas Case 2 has an acceleration of 0.8 m/s^2 due to the presence of opposing forces like friction.

In conclusion, if there are no other forces acting on block A, the acceleration will be greater compared to the scenario where additional opposing forces are present.