A ball is given an initial horizontal velocity and allowed to fall under the influence of gravity, as shown below. The work done by the force of gravity on the ball is: Ox \\ Work is done only if the applied force 0 is zero. 0 produces motion. 0 is greater than the weight. O none of these. Question 9 (2 points) _Il According to the scientific definition of work, pushing on a rock accomplishes no work unless there is 0 an applied force greater than its weight. 0 a net force greater than zero. 0 an opposing force. 0 movement in the same direction as the force. Why is it good to learn about renewable energy at school? 0 We'll never use renewable energy until it's too late. O The future of our lifestyle will depend on our adoption of renewable energy. 0 It's important to learn about renewable energy as it replaces other energy sources and becomes a significant part of our lives. Q Both B & C 0 none of these Question 2 (2 points) 1)) Listen I, Moving water can be used to produce electricity because _____________ . 0 most forms of energy can be converted into other forms. O energy cannot be converted into other forms. 0 potential energy can be converted into kinetic energy, but not vice versa. 0 kinetic energy can be converted into potential energy, but not vice versa. Water, wind and sunlight are all examples of _____________ that are available in Canada. 0 renewable resources 0 non-renewable resources 0 elements 0 none of these Question 4 (2 points) 1)) Listen u Which of the following is a practical use for solar energy? 0 Heating swimming pools 0 Cooking hot dogs O Powering road signs a All of these. What is the minimum work done when a 65 kg student climbs an 8.0 m-high stairway in 12 5? Question 14 (2 points) 4)) Listen h A 2 kg ball is rolled along the floor for 0.80 m at a constant speed of 6 m/s. What is the work done by gravity? A force of 25 N moves a 3.0 kg mass through a distance of 2.0 m in a straight line. The work done by the force is If a 7.00 kg object is lifted 6.00 m vertically upward in 4.00 5, what is the minimum work required? (9 = 10 1\"/52) A construction worker holds a heavy tool box. How much work is done by the worker? 0 Greater than zero 0 Less than zero 0 Zero What does "photo" mean in words like photosynthesis, photovoltaic and photograph? Question 6 (2 points) _II In which case below is work not being done? 0 pushing against an immovable wall 0 pushing a car a distance of 0.5 km 0 walking down a flight of stairs 0 playing a violin in an orchestra O gliding to a stop on roller skates A box of old textbooks is on the middle shelf in the bookroom 1.3 m from the floor. If the janitor relocates the box to a shelf that is 2.6 m from the floor, how much work does he do on the box? The box has a mass of 10 kg