Question

In the 1983 film, ”Risky Business”, the actor Tom Cruise slides across the polished hardwood floor in white tennis socks. The coefficient of kinetic friction between the socks and the floor is 0.23, and we’ll assume that Tom has a mass of 75 kg. a) (4 points) If he wants to get a running start and then slide across the floor for 2 m, how fast does he have to be at the moment he starts sliding? b) (3 points) If Tom were to lose 10 kg, would he need the same speed as in part (a) to slide for 2m? Explain your answer, and calculate the speed for this case, if it is different from part (a). c) (5 points) Tom is not satisfied with the result of his sliding, so he asks his manager to push him (instead of running). If the manager pushes him with a force of 250 N over a distance of 80 cm on the hardwood floor, how far will Tom slide after being pushed? Assume a mass of 75 kg again for this part. d) (4 points) If Tom were to lose 10 kg, would he slide the same distance as in part (c)? Explain your answer, and calculate the distance for this case, if it is different from part (c).

Answer 1

The reduction in mass does not have any effect on the speed and distance calculated in parts, b and d.