Answer:
Speed = 3 [km/h]
Explanation:
To solve this problem we must use the definition of speed which relates the distance traveled for a while.
Distance = 1.5 [km] = 1500 [m].
time = 0.5 [hr] = 1800 [s]
Speed = Distance/time
Speed = 1.5/0.5
Speed = 3 [km/h] or 1500/1800 = 0.8333[m/s]
I believe the correct answer from the choices listed above is the third option. <span>The force exerted by the book on the table is equal to the force exerted by the table which is 4.0 N. The book does not move so it must be that the forces are balanced. Hope this answers the question.</span>
∑F = ma = (90 kg)(1.2 m/s²) = 108 N = 100 N (1 significant digit)
