Question 1 (2 points) (use block-surface as the system) Alice applies a constant Force F of 15.0 N directed at 40 degrees below the horizontal on a crate moving on a rough horizontal flat surface. The mass of the crate is 4.00 kg. With her force, she continues to slide the crate from Ato B for a distance of 20 m, where it reaches a speed of 11.5 m/s. Determine the speed (m/s) of the block at A if the internal energy of the system increases by 95.5 J as the block moves from A to B. ROUGH C? 1.90 C? 3.67 .53. 5.15 8.07 Question 2 (2 points) (System is ball-earth) A ball of mass 1.5 kg is dropped from a height of 20 m from the ground. At a height of 4.0 m, what is the speed (m/s) of the ball? i O | l 20 m I | l | T I I 4 m (ii) 177 (ii) 122 [11:12 6-50 2.43 Question 3 (2 points) (System is child-earth) A 20 kg child slides down a winding water slide to a pool below. She starts at the top moving at 2.0 m/s and reaches the bottom moving at 4.5 m/s. If the water slide is considered frictionless, determine the height (m) of the slide where the child started. 0.83 1.41 C? 2.23 C? 3.42 Question 4 (2 points) (System is the springblock) A 0.80 kg block is permanently attached to a spring (k =1500 N/m) on a rough horizontal surface. The spring-block is initially stretched out to 15.0 cm from its equilibrium and released from rest. When the block slides 22.0 cm to the left from its release position, its speed is 2.73 m/s. Determine the work (J) done by friction. rough Question 5 (2 points) (System is spring-block-earth) A mass M = 8.00 kg block starts at the top of a smooth curved ramp and is released at rest as shown in the figure. It slides down the ramp and onto a horizontal floor that has a rough patch (Us = 0.230, pk = 0.350) of length 3.00 m and then continues to hit and compress a spring by 45.0 cm before rebounding. Determine the spring constant (N/m) of the spring. 2.0 m 245 C3. 736 C3. 1231 1500