Physics
Physics
Problem
Two small trolleys A and B move on a frictionless horizontal track in the same straight line. Initial data: • Trolley A: mass 5 kg, speed 4 m/s • Trolley B: speed 2.5 m/s, mass unknown The magnitudes of their momenta are equal. a. (i) Calculate the mass of trolley B. b. (ii) Both trolleys are brought to rest by the same constant opposing force acting for 2 s. Determine the magnitude of this force. c. (iii) Which trolley experiences the larger magnitude of deceleration? Justify mathematically.Intuitive explanation
The key insight is that momentum is the product of mass and velocity, so equal momenta doesn't mean equal masses or speeds—it's a constraint that links them. Since trolley A is heavier but slower than B, you need to set their momenta equal () and solve for B's unknown mass. This is a straightforward application of the momentum definition to find a missing quantity.
Intuitive explanation
The key insight is that momentum is the product of mass and velocity, so equal momenta doesn't mean equal masses or speeds—it's a constraint that links them. Since trolley A is heavier but slower than B, you need to set their momenta equal () and solve for B's unknown mass. This is a straightforward application of the momentum definition to find a missing quantity.