A 5 kg block on a frictionless horizontal surface experiences a net force of 12 N. What is its acceleration?

A 5 kg block on a frictionless horizontal surface experiences a net force of 12 N. What is its acceleration?

• A. 1.4 m/s^2
• B. 2.4 m/s^2
• C. 3.0 m/s^2
• D. 4.8 m/s^2

Answer: (B)

When a net force acts on a mass, the resulting motion is described by a = F_net / m. Here the block experiences a net horizontal force of 12 N and has a mass of 5 kg, so the acceleration is 12 / 5 = 2.4 m/s^2. On a frictionless horizontal surface there are no other horizontal forces, so all of the net force goes into speeding up the block in the force’s direction. The other numerical options would require different forces or masses, but with the given values, the acceleration is 2.4 m/s^2.

When a net force acts on a mass, the resulting motion is described by a = F_net / m. Here the block experiences a net horizontal force of 12 N and has a mass of 5 kg, so the acceleration is 12 / 5 = 2.4 m/s^2. On a frictionless horizontal surface there are no other horizontal forces, so all of the net force goes into speeding up the block in the force’s direction. The other numerical options would require different forces or masses, but with the given values, the acceleration is 2.4 m/s^2.