Answer:
B. 17.15 watts
Explanation:
Given that
Time = 10 seconds
height = distance = 0.7 meters
weight of sack = mg = F = 245 newtons
Power = work done/ time taken
Where work done = force × distance
Substituting the given parameters into the formula
Work done = 245 newton × 0.7 meters
Work done = 171.5 J
Recall,
Power = work done/time
Power = 171.5 J ÷ 10
Power = 17.15 watts
Hence the power expended is B. 17.15 watts
Answer:
True! First step is to make objective observations.
Newton's law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them. Newton's law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them.
Answer:
1.84 kJ (kilojoules)
Explanation:
A specific heat of 0.46 J/g Cº means that it takes 0.46 Joules of energy to raise the temperature of 1 gram of iron by 1 Cº.
If we want to heat 50 g of iron from 20° C to 100° C, we can make the following calculation:
Heat = (specific heat)*(mass)*(temp change)
Heat = (0.46 J/g Cº)*(50g)*(100° C - 20° C)
[Note how the units cancel to yield just Joules]
Heat = 1840 Joules, or 1.84 kJ
[Note that the number is positive: Energy is added to the system. If we used cold iron to cool 50g of 100° C water, the temperature change would be (Final - Initial) or (20° C - 100° C). The number is -1.84 kJ: the negative means heat was removed from the system (the iron).
According to Newton`s law. Force exerted by car,

After adding an additional 400 kg of mass, the force will be same therefore the acceleration

Thus, the acceleration after adding the masses is 1.47 \ m/s^2.