Answer: 166.67km/hr
Explanation:
Given the following :
Distance traveled = 250km
Time taken = 1.5 hours
Recall :
Speed = Distance traveled / time taken
Speed = 250 km / 1.5 hours
Speed = 166. 67 km/hr
Speed in m/s:
166.67km/hr = (166.67 × 1000)m / 3600 s
= 166670m / 3600s
= 46.3m/s
Answer:

Explanation:
Intensity is given by the expresion:

where:
Io = inicial intensity
r1= initial distance
r= final distance


Answer:
831.4 J
Explanation:
Info given:
mass adult: 82.5kg
mass child: 14.7kg
height of wall: 1.25m
g = 9.81m/s^2
PE = mgh
For adult:
mgh = (82.5kg)(9.81m/s^2)(1.25m) = 1011.65 J
For child:
mgh = (14.7kg)(9.81m/s^2)(1.25m) = 180.25 J
Difference in PE: 1011.65 J - 180.25 J = 831.4 J