(4%) Problem 16: A 65-kg skydiver jumps out of an airplane and falls 490 m, reaching a maximum speed of 56 m/s before opening her parachute. Randomized Variables m = 65 kg h = 490 m 1 = 36 m/s *50% Part (a) How much work, in joules, did air resistance do on the skydiver before she opened her parachute? W = Grade Sum Deductions Potential sin() cosO tan() TE ( ) 7 8 9 HOME cotan() Submissions asin() acos() E 4 5 6 Attempts ren atan() acotan( sinh 2 3 0% per atte detailed view cosh( anh() cotanh() 0 END O Degrees O Radians VO CLEAR W I Submit Hint Feedback I give up! Hints: 0% deduction per hint. Hints remaining: 1 Feedback: 0% deduction per feedback. 50% Part (b) Assuming the force of air resistance is constant, what is the magnitude of the force of air resistance, in newtons, on her? Fave = 429.65 Fave = 429.7 Correct!(6%) Problem 18: A block with mass m is released from rest at point A and slides down a curved slope to point B, then continues until it comes to rest at point C. The vertical height of A is h above point B, and point C is horizontal distance x from point B. The speed of the block at point B is 1B- -5 - B x * 50% Part (a) Write an expression for the work done by friction as the block slides from A to B. Your answer should be in terms of m, h, VB, and g (the acceleration due to gravity). W - 1 Grade Summary Deductions 0% Potential 100% B e ( 7 8 9 b d Submissions g 4 5 6 Attempts remaining: 996 h K 1 2 3 (0% per attempt) detailed view m P 0% S VB X 10% w 1 Submit Hint Feedback I give up! Hints: 0% deduction per hint. Hints remaining: 1 Feedback: 0% deduction per feedback $ 50% Part (b) Write an expression for the coefficient of kinetic friction between the block and the horizontal surface. Your answer should be in terms of r, VB, and g (the acceleration due to gravity). Feedback: is available. VB Oxg X Attempts Remain(5%) Problem 19: The diagram shows a crate with mass m = 29.8 kg being pushed up an incline that makes an angle q = 19.7 degrees with horizontal. The pushing force is horizontal, with magnitude P = 459 N. Starting from rest, the crate achieves a speed of 4.01 m/s as it moves a distance d = 6.39 m. P What is the work done by friction, in joules? W = 1 J Grade Summ Deductions Potential sino) cos() tan() TE ( 7 8 9 HOME Submissions cotan() asin() acos() E 4 5 6 Attempts rema atan() acotan() sinh() 1 2 3 (0% per attem detailed view cosh() tanh() cotanh() + 0 Degrees O Radians VO Submit Hint Feedback I give up! Hints: 0% deduction per hint. Hints remaining: 1 Feedback: 0% deduction per feedback.(4%) Problem 21: Suppose a 775-kg car climbs a 2.050 slope at a constant 30.5 m/s. 50% Part (a) What is the power output of the car P, in terms of the variables given in the problem statement, if the friction and wind resistance encountered is P = Grade Summary Deductions 0% Potential 100% cos ( a ) cos(Q) cos(0) 1 7 8 9 HOME Submissions sin(a) sin(Q) sin(0) 4 5 6 Attempts remaining: 995 1 2 3 (0% per attempt) detailed view d F g 0 0% m V VO 0% 0% Submit Hint I give up! 0% Hints; 0% deduction per hint. Hints remaining: 1 Feedback: 0% deduction per feedback. 50% Part (b) What is the power output of the car P, in watts, if F= 590 N? P = 26289.86 P = 2.629 x 104 Correct! F12 S &(5%) Problem 22: You give a crate of mass m = 1.00 kg an initial speed of vi = 4.00 m/s up an incline of 0 = 47.20. The crate then slides along the incline, reaches a spring of spring constant k = 70.9 N/m , and compresses the spring by As = 15.0 cm before stopping. y Vi m 25% Part (a) Assuming there is no friction, what is the distance, d, in meters, along the incline that the crate slides? d= 1.002 m Correct! 25% Part (b) What distance, ds, in meters, had the crate moved when it just touched the spring? ds = 0.8520 m / Correct! 25% Part (c) If there were friction between the crate and incline, which of the options below would be the correct equation for the magnitude of the kinetic friction force? fk = Himgcose Correct! 25% Part (d) If there were friction between the crate and incline, what value of the coefficient of kinetic friction would stop the crate after it travels a distance, ds, stopping just before it begins to compress the spring? HK = Grade Summary Deductions 0% Potential 100% sin() cos() tan( TE ( ) 7 8 9 HOME Submissions cotan() asin( acos() E 4 5 6 Attempts remaining: 998 (0% per attempt) atan() acotan() inho 1 2 3 detailed view cosh( tanh() cotanh() + 0 0% Degrees O Radians VO BACKSPACE DEL CLEAR Submit Hint Feedback I give up! FB F10