Question

20) A 80 kg adventurer ties a rope of length 1ta bodgs and fallsoff in s owing e ewn in the figure. The tension (in N) in the rope at the lowest point is a) 2100 b) 2200 c) 2300 d) 2400 e) 2500 21) Block A with mass mA 2 kg traveling at s 10 m/s to the right collides with block B with mass тв = 3 kg traveling at un®5m/st) the left. Afer the collision block A travels with a speed oft,- m/s to the left and block B with a speed of 's 7m's to the right. Which of the following staiemeni is correct? mtB a) The collision is a perfectly inclastic collision. b) The collision is an inelastic collision but not perfectly inelastic. e) The collision is an elastic collision. d) The collision is not possible. c) None of the above. A B distance 22) A block of mass m 2 kg is beld compressing a spring of force constant k - 00 nh through the 0.1 m on a rough surface as shown in the figure. The block is then released and goes is u cal loop of radius r-0.5 m. If the speed of the block at the top of the loop (point B) then how many joules are lost due to friction? b) 21 c) 19 d) 15 e) 11 23) A force-time curve for a baseball of mass 5 g struck by a bat is shown in the figure magnitude of the change in its momentum (in N.s? FIN) a) 50 b) 100 c) 150 d) 200 e) 250 23

please ask the professors to answer the questions quickly because this assignment must be delivered within one and a half hours

Answer 1

A change in momentum is known as impulse on the ball, which is given by I = integral F dt = area under curve I = area of triangle I = 1/2 times Base times height I = 1/2 times 5 times 40 I = 100 (N - s) option B is correct m = 2 kg k = 8000 N/m l = 0.1 m r = 0.5 m v_B = 3 m/s Here the spring energy imparted to the block is converted into the sum of friction energy Kinetic energy at B and potential energy at B spring energy = f_E + k e_B + p e_B implies 1/2 k x^2 = f_E + 1/2 m (v_B)^2 + m g (2 R) implies 1/2 times 8000 times 0.1^2 = f_E + 1/2 times 2 times 3^2 + 2 times 9.81 times (2 times 0.5) implies 40 = f_E + 9 + 19.62 implies f_E = 40 - 28.62 implies f_E = 11.38 J