Each multiple choice worth 2 Marks 2. A How much work must be done to stop an 1 800 kg vehicle travelling at 30 m/s? A. 1.8x10* J B. 5.4 x 10' J C. 5.3x 10' J D. 8.1x 105 J 3. C Work is measured in which units? A. B. N C. J/s D. N . S 4. A What is the minimum power developed by a 75 kg person who climbs a set of stairs 4.5 m high in 5.0 s? A. 6.8x10' W B. 6.6x10- W C. 1.7x103 W D. 3.3x10' W 5. A A 3.5 kg projectile was launched vertically at 75 m/s. The projectile reached a maximum height of 180 m. How much energy was lost to heat while the projectile was rising? A. OJ B. 3.7x10' J C. 6.2x10' J D. 9.8x 10' J