The total mechanical energy of the ball is the sum of its potential energy U and its kinetic energy K, therefore:

so, the total mechanical energy of the basketball is 118 J.
240
Explanation:
because 60 times 4 is 240
Explanation:
A.) Since Light doesn't bend until travelling through a different transparent medium, hence it won't pass when any opaque object is placed in front of it. Rubber tube being curved and opaque,won't let light pass through it.
B.) Since light always travels in a straight line, when tube is kept straight,there is a way for it to pass and the student can see it.
Answer:
Explanation:
Heres the correct and full question:
For a new TV series "Stupidity Factor contestants are dropped into the ocean (p=1030 kg/m³) along with a Styrofoam p=3oo kg/m³ block that is 2m x 3 m X 20 cm thick. If too many contestants climb aboard the block and it sinks below the water surface, they are declared "stupid" and abandoned at sea. Find the maximum number of 7o kg contestants that the block can hold. (No fractional contestants, please. They hate it when that happens.
answer:
volume of styrofoam block=V=2m x 3m x 0.20m =1.2m³
density of styrofoam=ρs=300kg/m³
mass of styrofoam=ms=v(ρs)=1.2 x 300=360kg
weight of styrofoam = ws=(ms)g=360 x 9.8=3528N
consider number of contestants= n
toatal weight of ccontestants=W=n(70 x 9.8)=n(686N)
since, styrofoam fully submerged into water, then bat force,
B=ρ(vs)g=1030 x 1.2 x 9.8 = 12112.8N
At equilibrium,
B - W - Ws = 0
12112.8 - 686n - 3528 = 0

n=12 person(contestants)