Question

17. A projectile of mass m is fired straight up from an initial height ho with an initial speod vo. The projectile rises to a maximum height of hesa and falls straight back down to the ground at zero height. What is the total work done by the force of gravity during this trajectory? Vo ho m. If a hole appears in 18. The water level in a city storagetower is at a height of 40 the tower at a beight of 25 m, what is the velocity of water flowing out of the B)4.9 m/s C) 294 m/s D) 17.1 m's E) 28 m/s A)9.8 m/s ah moving left with speed w/2 and Box 2 is moving right with speed v/2. What can you say total momentum and total kinetic energy (KE) during this collision? 19. Consider the following collision: Box 1 of mass m, moving to the right with speed v, collides with Box 2 of mass 3m, initially at rest. Immediately after the collision, Box about the 3m 3m 4 1 BEFORE AFTER A) Both total momentum and total KE are conserved. B) Neither total momentum, nor total KE are conserved C) Total momentum is conserved, but total KE decreased. D) Total momentum is conserved, but total KE increased. E) Total KE is conserved, but total momentum was not 20. A uniform horizontal plank of negligible mass and length L is supported by two supports at its ends. A mass mi is placed at the center of the plank and a mass mz is placed on the right end of the plank. What is the magnitude of the upward force exerted on the plank by LL2 the left support? (Hint: consider the torque with the right end as the axis.) E) None of these

Answer 1