General Physics 1, Additional questions By/ T.A. Eleyan (Lecture 13) General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [1] A 1300 kg car drives up a 17.0 m hill. During the drive, two nonconservative forces do work on the car: the force of friction, and the force generated by the car’s engine. The work done by friction is –3.31  105 J; the work done by the engine is +6.34  105 J. Find the change in the car’s kinetic energy from the bottom of the hill to the top of the hill. [2] A single conservative force Fx = (2x + 4) N acts on a 5kg particle, where x is in m. As the particle moves along the x axis from x = 1 m to x = 5 m, calculate (a) the work done by this force, (b) the change in the potential energy of the particle, and (c) its kinetic energy at x = 5 m if its speed at x =1m is 3 m/s. General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [3] Use conservation of energy to determine the final speed of a mass of 5.0kg attached to a light cord over a massless, frictionless pulley and attached to another mass of 3.5 kg when the 5.0 kg mass has fallen (starting from rest) a distance of 2.5 m as shown in Figure [4] A 5kg block is set into motion up an inclined plane as in Figure with an initial speed of 8 m/s.  The block comes to rest after travelling 3 m along the plane, as shown in the diagram.  The plane is inclined at an angle of 30' to the horizontal. (a) Determine the change in kinetic energy. (b) Determine the change in potential energy. (c) Determine the frictional force on the block. (d) What is the coefficient of kinetic friction? General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [5] A block with a mass of 3 kg starts at a height h = 60 cm on a plane with an inclination angle of 30', as shown in Figure. Upon reaching the bottom of the ramp, the block slides along a horizontal surface. If the coefficient of friction on both surfaces is ,Uk = 0.20, how far will the block slide on the horizontal surface before coming to rest? [6] Initially sliding with a speed of 1.7 m/s, a 1.7 kg block collides with a spring and compresses it 0.35 m before coming to rest. What is the force constant of the spring? [7] A horizontal force of 100 N is applied to move a 45-kg cart across a 9.0-m level surface. What work is done by the 100-N force?   General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [8] A Hooke’s law spring is compressed 12.0 cm from equilibrium and the potential energy stored is 72.0 J. What is the spring constant in this case?   [9] An object of mass m = 2.0 kg is released from rest at the top of a frictionless incline of height 3 m and length 5 m. Taking g = 10 m/s, use energy considerations to find the velocity of the object at the bottom of the incline. [10] A block of mass 1.0 kg is placed at the top of an incline of length 125 m and height 62.5 m. The plane has a rough surface. When the block arrives at the bottom of the plane it has a velocity of 25 m/ss. What is the magnitude of the constant frictional force acting on the block?  Take g = 10m/ss General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [11] A 0.2-kg pendulum bob is swinging back and forth. If the speed of the bob at its lowest point is 0.65 m/s, how high does the bob go above its minimum height? [12] Two objects are connected by a light string passing over a light frictionless pulley as shown in Figure. The object of mass 5.00 kg is released from rest. Using the principle of conservation of energy, (a) determine the speed of the 3.00-kg object just as the 5.00-kg object hits the ground. (b) Find the maximum height to which the 3.00-kg object rises. General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [13] A 5.00-kg block is set into motion up an inclined plane with an initial speed of 8.00 m/s. The block comes to rest after traveling 3.00m along the plane, which is inclined at an angle of 30.0° to the horizontal. For this motion determine the change in the block’s kinetic energy, (b) the change in the potential energy of the block–Earth system, (c) the friction force exerted on the block (assumed to be constant). (d) What is the coefficient of kinetic friction? General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [14] A block of mass 0.250 kg is placed on top of a light vertical spring of force constant 5 000 N/m and pushed downward so that the spring is compressed by 0.100 m. After the block is released from rest, it travels upward and then leaves the spring. To what maximum height above the point of release does it rise? [15] A single constant force acts on a 4.00-kg particle. (a) Calculate the work done by this force if the particle moves from the origin to the point having the vector position . Does this result depend on the path? Explain. (b) What is the speed of the particle at r if its speed at the origin is 4.00 m/s? (c) What is the change in the potential energy? [16] A potential-energy function for a two-dimensional force is of the form U = 3x3y + 7x. Find the force that acts at the point (x, y) General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [17] The coefficient of friction between the 3.00-kg block and the surface in Figure is 0.400. The system starts from rest. What is the speed of the 5.00kg ball when it has fallen 1.50 m [18] A 5-kg mass is attached to a light string of length 2m to form a pendulum as shown in Figure.  The mass is given an initial speed of 4m/s at its lowest position.  When the string makes an angle of 37o with the vertical, find (a) the change in the potential energy of the mass, (b) the speed of the mass, and (c) the tension in the string. (d) What is the maximum height reached by the mass above its lowest position? General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [19] A 20.0-kg block is connected to a 30.0-kg block by a string that passes over a light frictionless pulley. The 30.0-kg block is connected to a spring that has negligible mass and a force constant of 250 N/m, as shown in Figure. The spring is unstretched when the system is as shown in the figure, and the incline is frictionless. The 20.0-kg block is pulled 20.0 cm down the incline (so that the 30.0-kg block is 40.0 cm above the floor) and released from rest. Find the speed of each block when the 30.0-kg block is 20.0 cm above the floor (that is, when the spring is unstretched). General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [20] find the particle’s speed at points B, where the particle released from point A and slides on the frictionless track [21] Find the distance x. General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [22] An object of mass m starts from rest and slides a distance d down a frictionless incline of angleθ . While sliding, it contacts an unstressed spring of negligible mass as shown in Figure. The object slides an additional distance x as it is brought momentarily to rest by compression of the spring (of force constant k). Find the initial separation d between object and spring. [23] A 1.9-kg block slides down a frictionless ramp, as shown in the Figure. The top of the ramp is 1.5 m above the ground; the bottom of the ramp is h = 0.25 m above the ground. The block leaves the ramp moving horizontally, and lands a horizontal distance d away. Find the distance d. General Physics 1, Additional questions By/ T.A. Eleyan

General Physics 1, Additional questions By/ T.A. Eleyan [24] A skateboard track has the form of a circular arc with a 4.00 m radius, extending to an angle of 90.0° relative to the vertical on either side of the lowest point, as shown in the Figure. A 57.0 kg skateboarder starts from rest at the top of the circular arc. What is the normal force exerted on the skateboarder at the bottom of the circular arc? What is wrong with this picture? At bottom, a = v2/r Which direction? General Physics 1, Additional questions By/ T.A. Eleyan