Consider two cars, a 1,700 kg BMW and a 1,500 kg Mercedes-Benz. The BMW is speeding along at 120 km/h and the Mercedes-Benz is going half the speed at 60 km/h. If the two cars brake to a stop with the same constant acceleration, a. Is the amount of time required to come to a stop influenced by their initial velocity? Explain your answer using diagrams, equations, or any explanatory rules/principle b. Is the distance travelled prior to stopping influenced by their initial velocity? Explain your answer using diagrams, equations, or any explanatory rules/principles

You and four of your friends are all interested in getting out of town for a break. Two of your friends just want to relax while the other two want to get some exercise. You need some quiet time to study. To satisfy everyone, the group decides to spend the day canoeing on the river. Two people will put a canoe in the river and just drift downstream with the 1.5 km/h current. The second pair will begin at the same time as the first from 10. km downstream. They will paddle upstream until the two canoes meet. Since you have been canoeing with these people before, you know that they can paddle at 4.0 km/h in still water. When the two canoes meet, they will come to shore and you should be there to meet them with the picnic lunch. You decide to go to that spot ahead of time so you can study while you wait for your friends. How far from where the drifters launched will you wait for them? After lunch you decide to paddle across the river, which is 0.50 km wide. You can paddle 3.0 km/h in…

A woodpecker's brain is protected from high accelerations, and thus large forces, by tendon-like attachments inside the skull. While pecking on a tree, a woodpecker's head comes to a stop from an initial speed of 0.62 m/s in a distance of only 1.5 mm. Part A: Assuming contact acceleration, find the magnitude of its head's acceleration in multiples of g (g=9.90 m/s^2).  Part B: Calculate the stopping time of the woodpecker's head, in seconds.  Part C: The tendons cradling the woodpecker's brain stretch, making the brain's stopping distance 4.4 mm which is greater than the head's stopping distance. That results in a lower magnitude of acceleration for the brain. What is the magnitude of the brain's acceleration, expressed in multiples of g?

Part E Problem: Thinking and Investigation 44. In testing a new material to be used in non-slip door mats. Scientists made a mat made of this new material, and did the following experiment. A force (F) was used to pull a wooden block across the mat as shown below.(5) m μ The size of the force was varied and the data table below shows the size of the force and the block's resulting acceleration. F(N) (m/s²) 20 0.25 25 0.85 30 1.35 35 1.95 Plot the data on the graph below and draw a line of best fit. Extend the line back to the 'y' axis so that you have a y-intercept point and determine the slope of the line. F (N) The industrial standard for the coefficient of friction for non-slip mats is 0.85. a) Using your slope value and your y-intercept value from the graph, determine the coefficient of friction between the block and the mat. b) Would this mat be approved for production based on its coefficient of friction? Briefly explain. 11 of

Part A The equation F propeller. In fact, there are two contributions to the thrust one positive and one negative. The positive contribution comes from air pushed backward, away from the propeller (so dm/dt 0) at speed V, equal to the speed of the airplane through the air. km/h

how to do?

Determine the velocity of the crate when t = 4 s. Express your answer to three significant figures and include the appropriate units. The coefficient of kinetic friction between the 55-kg crate and the ground is μk = 0.3. The crate starts from rest, and P = 240 N. (Figure 1) Part A Figure 30° ✓ 1 of 1 НА ? v = Value Units Submit Request Answer Part B Determine the distance the crate travels when t = 4 s. Express your answer to three significant figures and include the appropriate units. НА ? 8 = Value Units Submit Request Answer Provide Feedback

A rocket with a mass of 2.70x106 kg exerts a vertical force of 3.40×107 N on the gases it expels. ▼ Part A Determine the acceleration of the rocket. Assume g remains constant, and ignore the mass of gas expelled (not realistic). Express your answer using two significant figures. VE ΑΣΦ Submit Dart R Request Answer ? m/s²

2. A block of mass m is moving with speed v along a horizontal surface when it collides with a uniform rod of mass 2m and length L attached at one end to a pivot. The surface and pivot have negligible friction. The rod is vertical when the block collides with the end of the rod. The block sticks to the rod, and the block-rod system rotates so that the end of the rod reaches a height h, as shown above. The total rotational inertia of the rod about the pivot is 2mL/3. Express answers in parts (a), (b), and (c) in terms of m, L, v, and physical constants as appropriate. 2m, L a. Derive an expression for the angular speed of the block-rod system immediately after the collision. b. Show that the change in height h of the bottom of the rod can be given by the equation A = 3v-/20g. c. Derive an expression for the mechanical energy dissipated during the collision.

It is friction that provides the force for a car to accelerate, so for high-performance cars the factor that limits acceleration isn't the engine; it's the tires. For the steps and strategies involved in solving a similar problem, you may view a Video Tutor Solution. Part A For typical rubber-on-concrete friction, what is the shortest time in which a car could accelerate from 0 to 50 mph? Suppose that us = 1.00 and k = 0.80. Express your answer with the appropriate units. 20 Submit μA Δt = |11.404 S Previous Answers Request Answer ? Review | Constants | Periodic Table X Incorrect; Try Again; 4 attempts remaining 7:54 PM