Force on Blocks: Fig. 5-1a & b, Mass 30 kg, Forces 28 & 14 N

[B-80]

Fig. 5-1a shows two blocks on a smooth surface. A constant horizontal force Fa is applied to block A, which pushes against block B with a 28.0 N force horizontally to the right. In Fig. 5-1b, the same force Fa is applied to block B so that block A pushes on block B with a 14.0 N force horizontally to the left. The blocks have a total mass of 30.0 kg.

Fig. 5-1

(a) What is the magnitude of the acceleration of the blocks in Fig. 5-1a?

what i tried was F=ma so 28=30a so 28/30=a

(b) What is the magnitude of the force Fa?

 

[Doc Al]

(a) What is the magnitude of the acceleration of the blocks in Fig. 5-1a?

what i tried was F=ma so 28=30a so 28/30=a

28.0 N is the force on block B (in case a), not on both blocks. You have to use all the information given to solve this. Hint: The same force pushes the same total mass in each case.

 

[m2003]

Fa is equal to 28 N in both scenarios, as stated in the problem. This is the force applied by block A on block B. It is also equal to the force applied by block B on block A in Fig. 5-1b.

(c) What is the acceleration of the blocks in Fig. 5-1b?

The acceleration in Fig. 5-1b can be calculated using the same formula, F=ma. In this case, the force is 14 N and the mass is still 30 kg, so the acceleration would be 14/30 = 0.467 m/s^2. However, it is important to note that this acceleration is in the opposite direction as in Fig. 5-1a, since the force is now being applied in the opposite direction.

(d) How does the mass of the blocks affect the acceleration in both scenarios?

The mass of the blocks does not directly affect the acceleration in either scenario. The acceleration is determined by the net force applied on the blocks. In both scenarios, the net force is 28 N, so the acceleration would be the same if the mass was different. However, the mass does affect the overall motion of the blocks, as objects with larger masses require more force to accelerate. In this case, the total mass of the blocks is 30 kg, so the force of 28 N is enough to accelerate them. If the mass was larger, a greater force would be needed to produce the same acceleration.