Let volume of empty boat be = 100% = 1V
and mass of boat be M
In water 10%, 0.1V of the volume is submerged.
Mass, m of 1200kg increases the submerging from 10%, 0.1V to 70%, 0.7V
M leads to 0.1V boat submerging
boat submerging.
M + 1200kg leads to 0.7V boat submerging.
This is 60%, 0.6 V increase
By comparison
(M+1200kg) * 0.1V = 0.7V * M
0.1M + 120kg = 0.7M
120kg = 0.7M - 0.1M
120kg = 0.6M
M = (120/0.6)kg
M = 200kg.
The mass of the boat is 200kg.
C. Thick wire and cold temperature.
Explanation:
The resistance of a wire is given by: R = (ρL)/A
where ρ is the resistivity of the material, L is the length of the wire, A is the cross-sectional area of the wire.
From the formula, we see that the thicker the wire, the larger A, therefore the smaller the resistivity. so, a thick wire will have lower resistivity.
Moreover, the resistance of a wire increases with the temperature. In fact, high temperatures mean more motion of the atoms/electrons inside the wire, so more resistance to the flow of current through it. Therefore, colder temperature means lower resistance.
So, the correct option is thick wire and cold temperature.
Answer:
C. The block and the sphere would have the same weight.
Explanation:
If both the block and the sphere weigh 7 kilograms then they have the same weight. They may look different, but they both weigh 7 kilograms.
Answer:
Earthworm lives in the soil, eats the soil which has organic matter such as decaying vegetation or leaves and crawls. While housefly lives in dirty places, feeds on faeces and flies.
Hope I get a brainliest answer.
Answer:

Explanation:
From the free-body diagram for the car, we have that the normal force has a vertical component and a horizontal component, and this component act as the centripetal force on the car:

Solving N from (2) and replacing in (1):

The centripetal acceleration is given by:

Replacing and solving for v:
