You testify as an expert witness in a case involving an accident in which car A slid into the rear of car B, which was stopped at a red light along a road headed down a hill (see the figure). You find that the slope of the hill is 0 = 11.0°, that the cars were separated by distance d = 24.0 m when the driver of car A put the car into a slide (it lacked any automatic anti-brake-lock system), and that the speed of car A at the onset of braking was vo = 20.0 m/s. With what speed did car A hit car B if the coefficient of kinetic friction was (a) 0.570 (dry road surface) and (b) 0.110 (road surface covered with wet leaves)?

A customer sits in an amusement park ride in which the compartment is to be pulled downward in the negative direction of a y axis with an acceleration magnitude of 1.52 g, with g = 9.80 m/s2. A 0.342 g coin rests on the customer's knee. Once the motion begins and in unit-vector notation, what are projections of the coin's acceleration relative to the ground on (a)x-axis, (b)y-axis, (c)z-axis and relative to the customer on (d)x-axis, (e)y-axis, (f)z-axis? (g) How long does the coin take to reach the compartment ceiling, 2.3 m above the knee? What are projections of the actual force on the coin on (h)x-axis, (i)y-axis, (j)z-axis and projections of the apparent force according to the customer's measure of the coin's acceleration on (k)x-axis, (I)y-axis, (m)z-axis?

A train pulls away from a station with a constant acceleration of 5.00 m/s2, after starting at rest. A ball of mass 3.20 kg hangs from a string attached to the ceiling of the train carriage. (1) Draw a sketch showing all the forces on the ball, indicating the direction of the acceleration vector. (2) Compute the angle that the string makes with the vertical.

An object undergoes one-dimensional motion along the x-axis subject to the the decelerating force dv kæv² m dt At time t = 0, the object's position is x = 0 and its velocity is v = v0. The decelerating force is a dv dv dx function of the object's position x(t) and velocity v(t). Using the fact that dt transform the dx dt problem into one having x as the independent variable. Solve for v as a function of x and v0 then determine the position xf at which the object comes to rest. If the object does not come to rest then xf = 00 (enter oo for infinity) dv = V = Xf = Question Help: O Message instructor Submit Question

You testify as an expert witness in a case involving an accident in which car A slid into the rear of car B, which was stopped at a red light along a road headed down a hill (see the figure). You find that the slope of the hill is 0 = 14.0°, that the cars were separated by distance d = 24.0 m when the driver of car A put the car into a slide (it lacked any automatic anti-brake-lock system), and that the speed of car A at the onset of braking was vo = 18.0 m/s. With what speed did car A hit car Bif the coefficient of kinetic friction was (a) 0.590 (dry road surface) and (b) 0.170 (road surface covered with wet leaves)? (a) Number i Units (b) Number i Units

A speedboat is cruising at a speed of 11.8 m/s in still water when it shuts off its engines and coasts to rest. The water exerts drag forces on the speedboat such that its speed during coasting is given by v = v₁e-ct, where v is the speed at time t, v, is the initial speed at t = 0, and c is a constant. At a time of t = 19.5 s after the engines are cut, the speed is 5.00 m/s. (a) What is the constant c (in s-¹) in the expression? -1 (b) What is the speed (in m/s) at t = 40.0 s? m/s (c) Given the expression above for the speed at any time, which of the expressions below gives the speedboat's acceleration while coasting? O OO a = -cv a = CV i a = -ce a = ce S a = cv -ct -ct

While watching the Minty Mania Grand Prix (the first race of the Marbula One 2020 season), you're curious about a few things. You notice that the marbles move downhill during the entire race (the slope of the track changes at different points), and then are lifted back to the starting line by a conveyor belt at the end of each lap. The announcer mentions that the conveyor belt lifts the marbles a height of 40.0 cm, at a constant speed of 0.095m/s, and that the length of the conveyor belt is 52 cm. He also mentions that the length of the track (from start line to finish line) is 10.26 m. You can assume that the marble is already moving at this speed when it starts moving up the conveyor belt. You also know that the mass of each racer (marble) is 6.6 g. To simplify the analysis, you decide to model the force of friction acting on the marble (due to interactions with the track, walls, and other marbles) as a constant 0.002 N force. To satisfy your curiosity, determine the power of the…

A car weighing 2.5 metric tons and traveling at 90 km/h hits a 500 m long stretch of black ice. Unfortunately, due to skidding, neither accelerating nor braking has any effect on the speed! The driver manages to maintain steady straight direction of motion and the only impact is provided by the ice friction force, which is numerically equal to 4v² Newtons, where the velocity v of the car is measured in m/sec. (a) Using Newton's Second Law F = ma, set up a mathematical model for the position x(t) and velocity v(t) of the car as functions of time t. Start by drawing a diagram and choosing a consistent system of units based on kg, m, sec (1 ton = 1000 kg, 1 m/sec = 3.6 km/h, 1 N = 1 kg · m/sec²). Introduce and label the variables, show the units and write down the differential equations and the intial conditions. (b) Use the model in part a to calculate v(t) and x(t). Fully show the process of solving the initial value problems. (c) Based on your work so far, how long will it take to pass…

= m = 2 kg boxes move along a conveyer belt at v = 3 m/s. The coefficient of friction between the boxes and the belt is us 0.4. When the emergency shutoff for the conveyer is triggered, it is desirable for the boxes to not slip. Assuming the emergency shutoff decelerates the belt at a constant rate, and all the belts are horizontal, what is the shortest shutoff time to ensure that no boxes slip? t = S Part 2 of 2 What would the minimum shutoff time be if somewhere along the belt there was a downward slope of 20°? t = S

You testify as an expert witness in a case involving an accident in which car A slid into the rear of car B, which was stopped at a red light along a road headed down a hill (see the figure). You find that the slope of the hill is 0 = 12.0°, that the cars were separated by distance d = 21.0 m when the driver of car A put the car into a slide (it lacked any automatic anti-brake-lock system), and that the speed of car A at the onset of braking was vo= 16.0 m/s. With what speed did car A hit car B if the coefficient of kinetic friction was (a) 0.520 (dry road surface) and (b) 0.110 (road surface covered with wet leaves)? (a) Number B Units (b) Number Units d vo Vo4 A