1. [-/5.5 Points] DETAILS MY NOTES The electric motor of a model train accelerates the train from rest to 0.600 m/s in 16.0 ms. The total mass of the train is 615 g. Find the average power delivered to the train during its acceleration. 2. [-/11 Points] DETAILS MY NOTES Force (N) 15 14/ 13 12 11 10 Position (m) -2 Consider the Force vs. Position graph above. This is a plot of a polynomial (linear) force function of the form F = (11 N) + (0.5 N/m).x What is the work done on a particle by the force as the particle moves from 1 m to 4 m? (t) Be extra careful with the sign. What is the work done on a particle by the force as the particle moves from 4 m to 1 m? (t) Be extra careful with the sign.3. [-/11 Points] DETAILS MY NOTES Force (N) 10 6 4 2 WILL Position (m) 1 2 3 5 6 7 8 Consider the Force vs. Position graph above. This is a plot of a polynomial force function of the form F = (4 N) + (2 N/m)-x + (0.03 N/m2)-x2 - (0.04 N/m3).x3 What is the work done on a particle by the force as the particle moves from 3 m to 6 m? (+) Be careful about the sign. - What is the work done on a particle by the force as the particle moves from 6 m to 3 m? (+) Be careful about the sign. -4. [-/22 Points] DETAILS MY NOTES A force of constant magnitude pushes a box up a vertical surface as shown in the figure. The box moves at a constant speed. If the mass of the box is 3.2 kg, it is pushed 2.9 m vertically upward, the coefficient of friction is 0.35 and the angle e is 30.0, determine the following. (a) work done on the box by F J (+) Be careful about the sign. (b) work done on the box by the force of gravity J (+) Be careful about the sign. (c) work done on the box by the normal force J (+) Be careful about the sign. (d) increase in gravitational potential energy of the system of the box and earth as the box moves up the wall 5. [-/16.5 Points] DETAILS MY NOTES A truck accelerates uniformly from rest to 23.0 m/s in 6.2 s along a level stretch of road. Determine the power required to accelerate the truck with a weight of 9.00 x 10# N . (a) The average power required is W (b) What is the constant force accelerating the truck? F = N (c) The instantaneous power required at the end of the time (t = 6.2 s) is W6. [-/6 Points] DETAILS MY NOTES A box of unknown mass is sliding with an initial speed v, = 4.20 m/s across a horizontal frictionless warehouse floor when it encounters a rough section of flooring d = 4.20 m long. The coefficient of kinetic friction between the rough section of flooring and the box is 0.100. Using energy considerations, determine the final speed of the box (in m/s) after sliding across the rough section of flooring. | m/'s 2 Tutorial 7. [-/16.5 Points] DETAILS MY NOTES You have a light spring which obeys Hooke's law. This spring stretches 3.04 cm vertically when a 2.70 kg object is suspended from it and stays at that position without moving. Determine the following. (a) the force constant of the spring (in N/m) N/m (b) the distance (in cm) the spring stretches if you replace the 2.70 kg object with a 1.35 kg object cm (c) the amount of work (in ]) an external agent must do to stretch the spring 8.30 cm from its unstretched position 8. [-/6 Points] DETAILS MY NOTES A box slides from rest down a frictionless ramp inclined at 30.0 with respect to the horizontal and is stopped at the bottom of the ramp by a spring with a spring constant of k = 1.50 x 104 N/m. point of release compression of spring If the box has a mass of 12.0 kg and slides 3.00 m from the point of release to the point where it comes to rest against the spring, determine the compression (in m) of the spring when the box comes to rest. m