سفينة على سطح الماء ترسل اشارة صوتية عموديا الى قعر الماء تستلم هذه الاشارة بعد 4 ثواني فما هو عمق القعر اذا علمت ان سرعة الصوت في الماء هي 1500متر / ثانية

11. you want to calculate the displacement of an object thrown over a bridge. using -10 m/s2 for acceleration due to gravity, what would be the total displacement of the object if it took 8 seconds before hitting the water?

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?