Question

Tom and Huck fashion a river raft out of logs. The raft is 2.90 m × 40 m × 0.150 m and is made from trees that have an average density of 700 kg/m3.

How many people can stand on the raft and keep their feet dry, assuming an average person has a mass of 70 kg? (Express your answer as an integer.)

Answer 1

**** Check this data*****  

raft seems impossibly big its breadth is very large = 40 m check this *****

and let me know because i did it with 40 m

Volume of raft =2.90 m × 40 m × 0.150 m =17.4 m³

the density of water = 1000 kg/m3

Buoyant force from water, F = 1000*17.4*9.8 = 170520 N

mass of raft = 17.4 *700 =12180 kg

If n = number of persons that the raft can hold before they start getting wet, then

weight of raft + weight of persons < buoyant force

12180*9.8 + 70*n*9.8 < 170520

n<74.5714

so number of person = 74