There is a disease known as formula fixation that is common among physics students. It particularly infects those who perceive physics as an applied math course where numbers and equations are simply combined to solve algebra problems. However, this is not the true nature of physics. Physics concerns itself with ideas and concepts that provide a reasonable explanation of the physical world. When students divorce the mathematics from the ideas, formula fixation takes root and even mathematical problem solving can become difficult. Do you have formula fixation? Test your health by trying these computational problems. 12. A force of 800 N causes an 80-kg fullback to change his velocity by 10 m/s. Determine the impulse experienced by the fullback. PSYW 13. A 0.80-kg soccer ball experiences an impulse of 25 N•s. Determine the momentum change of the soccer ball. PSYW 14. A 1200-kg car is brought from 25 m/s to 10 m/s over a time period of 5.0 seconds. Determine the force experienced by the car. PSYW 15. A 90-kg tight end moving at 9.0 m/s encounters a 400 N•s impulse. Determine the velocity change of the tight end. PSYW

12) I = 800 kg m/ s ,  13) Δv = 31.25 m / s, 14)  F = -3600 N , 15)  Δv = 4.44 m/s

Explanation:

In this strange exercise you are asked to answer a series of questions

12) force F = 800N applied mass m = 80 kg has a speed change of DV = 10 m / s, calculate the momentum

           I = Δp

           I = m Δv

           I = 80 10

           I = 800 kg m / s

13) a mass of m = 0.80 kg, has an impulse of 25 N s, determines the change in speed

          I = m Δv

          Δv = I / m

          Δv = 25 / 0.8

          Δv = 31.25 m / s

14) a mass m + 1200 kg is carried from 25 m / s to 10 m / s in a period of 5.0 s, determine the force

          I = m ( -v₀)

the proemd force for this impulse

          I = F t

we substitute

          F t = m (v_{f} -v₀)

          F = m (v_{f} -v₀ / t

          F = 1200 (10-25) / 5

          F = -3600 N

the negative sign indicates that the force is in the opposite direction of the movement

15) a mass = 90 kg with velocity v = 9.0 m has a momentum of I = 400N s, determines the change in velocity

           I = m Δv

           Δv = I / m

           Δv = 400/90

            Δv = 4.44 m / s

if they asked for the final speed it would be.

            I = m (v_{f} -v₀)

            v_{f} = v₀ + I / m

            v_{f} = 9 + 400/90

            v_{f} = 13.4 m / s

dang that balls went far