Answer:
12.5 km
Explanation:
Since 30.0 minutes is half of an hour and the average speed is 25.0 km/h we can multiply the time by the speed to find the distance travelled.
25.0km/h x 0.5 hours = 12.5 km
The force the box is exerting on Manuel is the weight of the box, downward:

and this force is perfectly balanced by the constraint reaction applied by Manuel's hand, pushing upward.
Answer:
2000 kg
Explanation:
Given that Which will have a larger momentum when moving at the same speed: a 2,000-kg truck or a 1,000-kg sedan
According to the definition of momentum, momentum is the product of mass and velocity.
That is,
Momentum = mass × velocity
Since velocity or speed is the same, then, the one of higher mass will have a greater momentum.
Therefore, the 2000 kg truck will have the greater momentum.
Wood isn't as tough as rock. Wood also breaks down in weather and cracks under pressure. Plus rocks were more accessible.