Answer:
The work done shall be 14715 Joules
Explanation:
The work done by a force 'F' in a displacement 'dy' is given by

At any position 'y' the weight shall be sum of weft of water and weight of string

Thus applying values we get

Answer:
a) F = 527.65 N, Force applied is upwards.
b)F = - 527.65 N, where, negative sign depicts Force is applied downwards.
Explanation:
Data provided:
Weight of the firefighter = 756 N
Mass of the firefighter = 756/9.8 = 77.14 Kg
Acceleration, a = 2.96 m/s²
a) In the absence of the pole the firefighter would have been moving down with an acceleration of 9.8 m/s (i.e the acceleration due to the gravity), but due to the presence of the pole the acceleration of the firefighter has been reduced. thus, a force is applied by the pole on the firefighter to reduce the acceleration.
therefore, we have
F = ma(net) = 77.14 × (9.8-2.96) = 527.65 N, Force applied is upwards.
B) According to the Newton's third law, the force will be equal and opposite to the force in the part a)
thus, we have
F = - 527.65 N
Answer:
The average number of calories needed daily represents the average quantity of calories eliminated by human body due to metabolism and must be compensated by eating and drinking.
The amount of calories contained in the food we eat every day must represent the amount of calories eliminated by the body in that time to have a steady weight.
Explanation:
The average number of calories needed daily represents the average quantity of calories eliminated by human body due to metabolism and must be compensated by eating and drinking. If total quantity of calories in the food we consume every day is higher that the average number of calories needed daily, then weight increases by fat accumulation.
Explanation:
Given:
v₀ = 250 mph
v = 0 mph
t = 25 s
Find: a
v = at + v₀
(0 mph) = a (25 s) + (250 mph)
a = -10 mph/s
Answer: D. 0.57
Explanation:
The formula to calculate the eccentricity
of an ellipse is (assuming the moon's orbit in the shape of an ellipse):

Where:
is the apoapsis (the longest distance between the moon and its planet)
is the periapsis (the shortest distance between the moon and its planet)
Then:


This is the moon's orbital eccentricity