Answer:
A. Remove everything in the refrigerator to lighten the load.
B. Put a lubricant between the surface of the object and the floor
C. Use round objects, like pencils , to decrease the friction and push the refrigerator over the pencils more easily
Explanation:
Force of friction is a resistance force which acts between two surfaces which are in relative motion. Friction is both boon and bane. Due to friction, we are able to sit, walk etc but also, due to friction there is dissipation of energy. Friction can be reduced by applying lubricants, reducing contact area, reducing the load.
F = μN where N is the normal force which depends on the mass.
Thus, by reducing the load, force of friction can be reduced. Round objects like wheels can also be used. By this the contact area reduces.
<span>7.7 m/s
First, determine the acceleration you subject the sled to. You have a mass of 15 kg being subjected to a force of 180 N, so
180 N / 15 kg = 180 (kg m)/s^2 / 15 kg = 12 m/s^2
Now determine how long you pushed it. For constant acceleration the equation is
d = 0.5 A T^2
Substitute the known values getting,
2.5 m = 0.5 12 m/s^2 T^2
2.5 m = 6 m/s^2 T^2
Solve for T
2.5 m = 6 m/s^2 T^2
0.41667 s^2 = T^2
0.645497224 s = T
Now to get the velocity, multiply the time by the acceleration, giving
0.645497224 s * 12 m/s^2 = 7.745966692 m/s
After rounding to 2 significant figures, you get 7.7 m/s</span>
<u>Given data</u>
Source temperature (T₁) = 177°C = 177+273 = 450 K
Sink temperature (T₂) = 27°C = 27+273 = 300 K
Energy input (Q₁) = 3600 J ,
Work done = ?
We know that, efficiency (η) = Net work done ÷ Heat supplied
η = W ÷ Q₁
W = η × Q₁
First determine the efficiency ( η ) = ?
Also, we know that ( η ) = (T₁ - T₂) ÷ (T₁)
= 33.3% = 0.333
Now, Work done is W = η × Q₁
= 0.33 × 3600
<em> W = 1188 J</em>
<em>Work done by the engine is 1188 J</em>
Im not for sure but i think it takes a couple hundred years (or according to the climate)
