Answer:
16.1 N
Explanation:
From the question,
F = ma.............................. Equation 1
Where F = horizontal force, m = mass of the object, a = acceleration .
Given: m = 7.0 kg, a = 2.3 m/s²
Substitute this values into equation 1
F = (7.0×2.3)
F = 16.1 N.
Hence the magnitude of the horizontal force is 16.1 N
The density of seawater plays a vital role in causing ocean currents and circulating heat because of the fact that dense water sinks below less dense. long story short, seawater is the problem because its denser than pure water.
The amount of heat given by the water to the block of ice can be calculated by using

where

is the mass of the water

is the specific heat capacity of water

is the variation of temperature of the water.
Using these numbers, we find

This is the amount of heat released by the water, but this is exactly equal to the amount of heat absorbed by the ice, used to melt it into water according to the formula:

where

is the mass of the ice while

is the specific latent heat of fusion of the ice.
Re-arranging this formula and using the heat Q that we found previously, we can calculate the mass of the ice:
<span>A motor produces less mechanical energy than the energy it uses because the motor looses some energy to heat.</span>