Answer:
45 W
Explanation:
First of all, we need to find the work done by the person to lift the bag. The work done is given by
where
F = 75.0 N is the force applied
d = 1.50 m is the displacement of the bag
Substituting numbers into the formula,
Now we can find the power used, which is given by
where
t = 2.50 s is the time taken
Again, using W=112.5 J, we find
Answer:
a. 1.5 m/s
Explanation:
We will apply the law of conservation of energy in this situation between the initial position and the lowest point of the swing:
where,
m₁ = mass of ball = 1.6 kg
m₂= mass of block = 0.8 kg
u₁ = initial speed of ball = 0 m/s
u₂ = initial speed of block = 0 m/s
v₁ = final speed of ball = ?
v₂ = final speed of block = 3 m/s
Therefore,
v₁ = 1.5 m/s
Therefore, the correct option is:
<u>a. 1.5 m/s</u>