3 m B Prob. 15-42

The motor, M, pulls on the cable with a force F = (101² + 300)N, where t is in seconds. If the 100 kg crate is originally at rest at 1 = 0, determine its speed when t = 4 s. Hint: First find the time needed to begin lifting the crate.

Q17. As shown in the image below, the 0.7-kg ball strikes the rough ground and rebounds. The directions of its velocities before and after the strike are shown. If the speeds are v₁ = 27 m/s and v₂ = 12 m/s, determine the magnitude of the impulse (in N.s) the ground exerts on the ball. Assume that the ball does not slip when it strikes the ground, and neglect the size of the ball and the impulse produced by the weight of the ball. Please pay attention: the numbers may change since they are randomized. Your answer must include 2 places after the decimal point. V₁ Your Answer: 45° Answer 30° 02

The 64.4-lb slider moves in the vertical plane on a smooth rail. The spring with k = 800 lb/ft is unstretched with the slider at point B. If the slider is released from rest at point A, what is the speed at point C? The slider can be approximated as a particle. 인 it woll 3 ft C abert --www- A B 3 ft

A toboggan having a mass of 12 kg starts from rest at A and carries a girl and boy having a mass of 40 kg and 45 kg, respectively. When the toboggan reaches the bottom of the slope at B, the boy is pushed off from the back with a horizontal velocity of vỏ/t = 2 m/s, measured relative to the toboggan. Suppose that h = 3.2 m. Neglect friction in the calculation. (Figure 1) Figure B vbil A h Part A Determine the velocity of the toboggan afterwards. Express your answer to three significant figures and include the appropriate units. Vt = Submit Value Provide Feedback Request Answer Units ?

5. The 8-kg smooth collar has a speed of 5 m/s when it is at s = 0. Determine the maximum distance s it travels before it stops momentarily. The spring has an unstretched length of 2 m. -1.5 m- -3 m/s k = 100 N/m