A body is projected downward at an angle of 30 degrees with the horizontal from the top of the building 170 m high. Its initial speed is 40 m/s. How long will it take before striking the ground? * (2 Points} 0 None of the Above A T-kg object is subjected to two forces, F1=20i+30j N and F2=8i-50j N. Find the acceleration of the object. * (2 Points) 0 None of the Above 3 A rifle bullet has a muzzle velocity of 680 ft/s. If it is aimed 45 degrees from the horizontal, it will reach its maximum range. Evaluate the maximum range. * (2 Points) 14 450 ft 12 260 ft 16 430 ft 15 390 ft None of the Above9 In the figure, the 8-kg object is subject to the forces F1=30 N and F2=40 N. Find the acceleration of the object. * (2 Points) 70 F2 O a = 4.6i - 2.3j " O a = 3.2i - 4.2jm O a = 5.27 + 4.7j " O a = 2.6i + 4.3j " None of the Aboveii] A 400-9 block originally moving at 12- cm/s coasts 70 cm along a tabletop before coming to rest, What is the coefcient of friction between block and table? * (2 Points). O None of the Above A 1.00-kg brick rests on the surface of the Earth at the equator (6378 km). Calculate the following: (a) the gravitational force on the brick, (b) the centrifugal force on the brick, (c) the weight of the brick, (d) the acceleration due to gravity, (e) centrifugal acceleration. {e} free-fall acceleration. (Non-anonymous question1 * {10 Points} An inclined plane making an angle of 25 degrees with the horizontal has a pulley at its top. A 30-kg block on the plane is connected to a freely hanging 20-kg block by means of a cord passing over the pulley. Compute the distance the 20-kg block will fall in 2 s starting from rest. Neglect friction. * (2 Points) 4 B 25 2.34 m 2.88 m 3.24 m 3.65 m None of the AboveA projectile is red with initial velocity 95 m/s at an angle of 50 degrees from the horizontal. After 5 s. it strikes the top of a hill. What is the elevation of the hill above the point of ring? * (2 Points) 0 None of the Above A baseball is thrown with an initial velocity of 100 m/s at an angle of 30 degrees above the horizontal. How far from the throwing point will the baseball attain its original level? * (2 Points) 0 None of the Abowe A body projected upward from level ground at an angle of 50 degrees with the horizontal has an initial speed of 40 m/s. How long will it be before it hits the ground? * (2 Points) O 4.555 O 5.325 O 6.245 O 7.235 0 None of the Above 6 On the figure, the two boxes have identical masses, 40 kg. Both experience a sliding friction force with u = 0.15. Find the acceleration of the boxes. * (2 Points) 0.87 mg 30 30 0.5 mg mg O 0.872 1.08 1.50 1.35 2 None of the Above