Final answer:
To calculate the force of friction acting on a cart that slows down due to friction, divide the change in velocity by time to get acceleration, then multiply by the mass of the cart. For a 0.5 kg cart slowing down by 0.15 m/s over 2.25 s, the force of friction is -0.03335 N.
Step-by-step explanation:
To find the force of friction acting on a cart that has decreased its velocity during a certain time period, we want to use the concept of acceleration and Newton's second law of motion. The acceleration a can be calculated by the change in velocity Δv divided by the time t, which is a = Δv / t. Then, using Newton's second law, F = ma, where F is the force, m is the mass, and a is the acceleration, we can determine the force of friction. Here, the mass of the cart m is 0.5 kg, the change in velocity Δv is -0.15 m/s, and the time t is 2.25 s. So, acceleration a is -0.15 m/s / 2.25 s = -0.0667 m/s². The negative sign indicates that this is a deceleration. Finally, the force of friction F is (0.5 kg)(-0.0667 m/s²) = -0.03335 N. The negative sign here indicates that the friction force is opposing the initial direction of motion.