16. [-/0.5 Points] DETAILS SERPSE10 4.3.Op.013.MI. MY NOTES A placekicker must kick a football from a point 36.0 m (about 40 yards) from the goal. Half the crowd hopes the ball will clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 20.2 m/s at an angle of 48.09 to the horizontal. (a) By how much does the ball sbar? (Enter a negative answer if it falls short.) m b) Does the ball approach the crossbar while still rising or while falling? rising O falling Need Help? Master It 17. [-/1 Points] DETAILS KATZPSEF1 5.P.065. MY NOTES A box with mass m, = 8.00 kg sliding on a rough table with a coefficient of kinetic friction of 0.230 is connected by a massless cord strung over a massless, frictionless pulley to a second box of mass my = 13.0 kg hanging from the side of the table (see figure below). What is the tension in the cord connecting the boxes? N 18. [-/1 Points] DETAILS KATZPSEF1 5.P.071. MY NOTES A block of ice (m = 11.0 kg) with an attached rope is at rest on a frictionless surface. You pull the block with a horizontal force of 80.0 N for 1.40 s. (a) Determine the magnitude of each force acting on the block of ice while you are pulling. pull = N Fa N IN b) with what speed is the ice moving after you are finished pulling? m/s 19. [-/1 Points] DETAILS KATZPSEF1 5.P.076. MY NOTES Jamal and Dayo are lifting a large chest, weighing 170 lb, by using the two rope handles attached to either side. As they lift and hold it up so that it is motionless, each handle makes a different angle with respect to the vertical side of the chest (see figure below). If the angle between Jamal's handle and the vertical side is 25.0 and the angle between Dayo's handle and the vertical side of the chest is 30.0, what are the tensions in each handle? (Due to the nature of this problem, do not use rounded intermediate values in your calculations-including answers submitted in WebAssign.) N21. [-/0.5 Points] DETAILS SERPSE 10 5.7.OP.014. MY NOTES The systems shown below are in equilibrium with m = 1.70 kg and 8 = 32.0. If the spring scales newtons, what do they read? Ignore the mass are frictionless. m m m d scale in (a): scale in (b): scale in (c): scale in (d): Need Help? Watch It23. [-/1 Points] DETAILS SERPSE10 5.7.OP.015.MI. MY NOTES Assume the three blocks (m, = 1.0 kg, m2 = 2.0 kg, and m; = 3.5 kg) portrayed in the figure below move on a frictionless surface and a force F = 40 N acts as shown on the 3.5 kg block. F m3 (a) Determine the acceleration given this system (in m/s to the right). m/s2 (to the right) (b) Determine the tension in the cord connecting the 3.5 kg and the 1.0 kg blocks (in N). (c) Determine the force exerted by the 1.0 kg block on the 2.0 kg block (in N). N (d) what If? How would your answers to parts (a) and (b) of this problem change if the 2.0 kg block was now stacked on top of the 1.0 kg block? Assume that the 2.0 kg block sticks to and does not slide on the 1.0 kg block when the system is accelerated. (Enter the acceleration in m/s2 to the right and the tension in N.) acceleration Im/s' (to the right) tension IN Need Help? Master It 24. [-/0.5 Points] DETAILS KATZPSEF1 6.P.063. MY NOTES A force of 82.0 N in the horizontal direction is required to set a 38.0-kg box, initially at rest on a flat surface, in motion. After the box begins to m ce of 64.6 N is required to maintain a constant speed. (a) What is the coefficient of static n the box and the surface? (b) What is the coefficient of kinetic friction between the box and the surface?24. [-/0.5 Points] DETAILS KATZPSEF1 6.P.063. MY NOTES A force of 82.0 N in the horizontal direction is required to set a 38.0-kg box, initially at rest on a flat surface, in motion. After the box begins to move, a horizontal force of 64.6 N is required to maintain a constant speed. (a) What is the coefficient of static friction between the box and the surface? (b) What is the coefficient of kinetic friction between the box and the surface? 25. [-/1 Points] DETAILS SERPSE10 5.7.OP.022. MY NOTES An elevator car has two equal masses attached to the ceiling as shown. (Assume m = 3.10 kg.) m fa T2 m A (a) The elevator ascends with an acceleration of magnitude 1.80 m/s". What are the tensions in the two strings? (Enter your answers in N.) T1= N T, = N (b) The maximum tension the strings can withstand is 79.8 N. What is the maximum acceleration of the elevator so that a string does not break? (Enter the magnitude in m/s2.) m/s21. [-/1 Points] DETAILS SERPSE 10 8.3.P.007.MI. MY NOTES PRACTICE ANOTHER A crate of mass 9.8 kg is pulled up a rough incline with an initial speed of 1.52 m/s. The pulling force is 102 N parallel to the incline, which makes an angle of 20.50 with the horizontal. The coefficient of kinetic friction is 0.400, and the crate is pulled 5.02 m. (a) How much work is done by the gravitational force on the crate? (b) Determine the increase in internal energy of the crate-incline system owing to friction. (c) How much work is done by the 102-N force on the crate? d) What is the change in kinetic energy of the crate? e) What is the speed of the crate after being pulled 5.02 m? m/s Need Help? Master It 2. [-/1 Points] DETAILS SERPSE10 8.2.P.003. MY NOTES PRACTICE ANOTHER A block of mass m = 5.10 kg is released from rest from point @ and slides on the frictionless track shown in the figure below. (Let h, = 5.50 m.) 3.20 m 2.00 m a) Determine the block's speed at points B and C VB = m/s VC= m/s (b) Determine the net work done by the gravitational force on the block as it moves from point @ to point @. Need Help? Watch It 3. [-/0.5 Points] DETAILS SERPSE10 8.4.OP.009. MY NOTES PRACTICE ANOTHER A child on a tricycle is moving at a speed of 1.40 m/s at the start of a 2.05 m high and 12.4 m long incline. The total mass is 53.5 kg, air resistance and rolling resistance can be modeled as a constant friction force of 41.0 N, and the speed at the lower end of the incline is 6.40 m/s. Determine the work done (in ]) by the child as the tricycle travels down the incline.4. [-/1 Points] DETAILS SERPSE10 7.5.P.021. MY NOTES PRACTICE ANOTHER A 0.700-kg particle has a speed of 1.20 m/s at point @and kinetic energy of 7.60 J at point B a) What is its kinetic energy at ? b) What is its speed at B m/s (c) what is the net work done on the particle by external forces as it moves from @ to B? Need Help? Watch It 5. [-/1 Points] DETAILS SERPSE10 8.3.OP.008. MY NOTES PRACTICE ANOTHER A block of mass m = 2.00 kg is attached to a spring of force constant k = 425 N/m as shown in the figure below. The block is pulled to a position x; = 5.40 cm to the right of equilibrium and released from rest. WWWWWW m x=0 x=x a) Find the speed the block has as it passes through equilibrium if the horizontal surface is frictionless. m/s b) Find the speed the block has as it passes through equilibrium (for the first time) if the coefficient of friction between block and surface is /k = 0.350. m/s Need Help? Watch It 6. [-/1 Points] DETAILS SERPSE10 8.4.OP.012. MY NOTES PRACTICE ANOTHER A toy cannon uses a spring to project a 5.38-g soft rubber ball. The spring is originally compressed by 4.99 cm and has a force constant of 8.10 N/m. When the cannon is fired, the ball moves 14.9 cm through the horizontal barrel of the cannon, and the barrel exerts a constant friction force of 0.032 5 N on the ball. (a) With what speed does the p the barrel of the cannon? m/s (b) At what point does the ball have maximum speed? cm (from its original position) c) What is this maximum speed? m/s Need Help? Watch It