A horizontal force of 140 N is needed to pull a 60kg box across the horizontal floor at constant speed . Find the coefficient of
1 answer:
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Answer:
t = 16.5s
Explanation:
Given parameters:
Acceleration = 3.1m/s²
Initial velocity = 0m/s
Final velocity = 51m/s
Unknown:
Time taken = ?
Solution:
To solve this problem we need to reiterate that acceleration is the rate of change of velocity with time.
So;
Acceleration =
v is the final velocity
u is the initial velocity
t is the time taken
So;
3.1 =
3.1t = 51
t = 16.5s
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:
where
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
Re-arranging this formula and using the heat Q that we found previously, we can calculate the mass of the ice: