Scin233 K001 Fall 2023 Week 7

Scin233 K001 Fall 2023 Week 7/8 Assignment Luke Dills 12/18/2023 Ch9. #18 . An elephant and a hunter are having a confrontation. M E =2000kg, V E =7.5m/s, M H =90kg, V H =7.4m/s, M D =0.04kg, V D =600m/s. a. Calculate the momentum of the 2000.0-kg elephant charging the hunter at a speed of 7.50 m/s. 2000x7.5= (15000kg * m/s)i b. Calculate the ratio of the elephant’s momentum to the momentum of a 0.0400-kg tranquilizer dart fired at a speed of 600 m/s. 0.04x600= (24kg * m/s)-i The ratio of the magnitude of the momentum of elephant and the momentum of the dart is 15000/24=625 c. What is the momentum of the 90.0-kg hunter running at 7.40 m/s after missing the elephant? 90x7.4=(666kg*m/s)i #30. A 0.450-kg hammer is moving horizontally at 7.00 m/s when it strikes a nail and comes to rest after driving the nail 1.00 cm into a board. Assume constant acceleration of the hammernail pair. J=F avg t = m(v 2 -v 1 ), v=u+at, v 2 -u 2 =2as a. Calculate the duration of the impact. (0m/s 2 -7m/s 2 )/2(1cm)= -24.5x10 2 m/s 2 t=(0m/s 2 -7m/s 2 )/- 24.5x10 2 m/s 2 = 0.0028s b. What was the average force exerted on the nail? (0.45kg x 7m/s)/0.003s= 1050N #36. Two identical pucks collide elastically on an air hockey table. Puck 1 was originally at rest; puck 2 has an incoming speed of 6.00 m/s and scatters at an angle of 30 o with respect to its incoming direction. What is the velocity (magnitude and direction) of puck 1 after the collision? m 1 v 1 =m 1 v 1 cos q 1 +m 2 v 2 cos q 2 , KE initial =1/2m 1 v 2 1 , KE final = 1/2m 1 v 2 1 +1/2m 2 v 2 2 . V=3m/s at 60 o below the x axis.

#56. Two asteroids collide and stick together. The first asteroid has mass of 15x10 3 and is initially moving at 770 m/s. The second asteroid has mass of 20x10 3 and is moving at 1020 m/s. Their initial velocities made an angle of 20° with respect to each other. What is the final speed and direction with respect to the velocity of the first asteroid? Momentum before collision: p i =m 1 v 1 i+m 2 [v 2 cos q i+v 2 sin q j] momentum after collision: P f (m 1 +m 2 )v f V f =([m 1 v 1 +m 2 v 2 cos q ]i+v 2 sin q j)/(m 1 +m 2 ) V f =sqrt/(v 2 f,x +v 2 f,y ) Final velocity= 900m/s direction of the final speed of the system: tan f =(v f,y )/(v f,x ), f= tan -1 (199.35888/877.06556) =12.8 o #64. Two particles of masses m 1 and m 2 separated by a horizontal distance D are released from the same height h at the same time. Find the vertical position of the center of mass of these two particles at a time before the two particles strike the ground. Assume no air resistance. M 1 g(h-y)+m 2 g(h-y)=(1/2)m 1 v 2 1 +(1/2)m 2 v 2 2 V 1 =gt, v 2 =gt M 1 +m 2 )g(h-y)=(1/2)(m 1 +m 2 )(gt) 2 , h-y=(1/2)gt 2 , y=h-(1/2)gt 2 Y=position, h= initial height, g= acceleration due to gravity, t= time before impact. Ch10. #30. A wheel rotates at a constant rate of 2x103 rev/min. What is its angular velocity in radians per second? ( 2p rad/rev)(2000/60)=209.44rad/s Angular velocity=209.4 Through what angle does it turn in 10 s? Express the solution in radians and degrees 209.44x10=2094.4rad, 2094.4x(180/ p )= 119,967.18 o The wheel turns through an angle of approximately 2,094.4radians in 10seconds.