4. A boy throws a softball of 0.25 kg straight up into the air. It reaches a maximum altitude of 15 m and then returns to the boy's hand. Calculate the velocity of the ball when it returns to the boy's hand. (Hint: Use the principle of the Conservation of Energy)

ks Classes A4 A 2 kg object moves with a velocity of 4 m/s for a time of 10 seconds. How much KE does the object possess? 1 Ex = -_-mv² 2 E = kinetic energy of object m = mass of object v= speed of object 16 w 16 J 8 J 8 W ch F2 #3 3 F3 $ 4 Y F4 II F5 % 5 F6 A 6 DELL F7 & 7 8 F8 * CO F9 prt sc 9 F10

* Incorrect. A proton (mass m = 1.67 × 10-27 kg) is being accelerated along a straight line at 2.00 × 10¹1 m/s² in a machine. If the proton has an initial speed of 1.30 x 105 m/s and travels 5.60 cm, what then is (a) its speed and (b) the increase in its kinetic energy? (a) Number i 3.28E-22 (b) Number i Units Units J

Calculate the kinetic energy of a 300 g baseball thrown at a velocity of 44 m/s. NAS 440 J 290 J 580 J 510 J 13.2 J

Releasing some frustration at the end of the semester, you throw your physics book (mass of 4.3 kg) off of a 24 m tall building. You throw your book so that it has a speed of 3 m/s right after you let go. What is the kinetic energy of your book after you let go? (in J) 12.9 1.01×103 206 0 19.4 How how fast is your textbook moving right before it lands? For now, ignore friction. (in m/s) 21.9 17.5 24.7 21.5 If friction is NOT negligible, and 350 J of the textbook's energy is converted to thermal energy as it falls, how fast is it moving just before it lands? (in m/s) 17.8 17.5 12.8 25.3 25.0

A bird is flying at 3 m/s and its mass m=0.8 kg. Determine its Kinetic Energy. Include units

Galileo does an experiment. He goes to the top of the leaning tower of pisa and drops a concrete ball and a wooden ball of equal size.The concrete ball has twice the mass of the wooden ball. How do the kinetic energies of the balls compare as they reach the ground? a) The wooden one has four times as much kinetic energy as the other does. b) The wooden one has twice as much kinetic energy as the other does. c) The wooden one has the same kinetic energy as the other does. O d) The wooden one has one fourth as much kinetic energy as the other does. O e) The wooden one has one half as much kinetic energy as the other does. (