Answer:
The acceleration at lowest point is 19.62 m/s^2
Explanation:
Conservation of energy is an concept in which it is stated that the energy of an isolated object remains the same. Energy changes from one form to another.
Lets Assume
Constant of string is K
By using the conservation of energy we will have the following equation
1/2 x 80^2 x K = m x 9.81 x 120
3200 K = 1177.2 m
K = 1177.2 m / 3200
K = 0.368 m
At the lowest point we will have
a = ( K x X - m x g ) / m
a = ( 0.368 m x 80 - m x 9.81 ) / m
a = 19.62 m / s^2
So, the acceleration at lowest point is 19.62 m/s^2
Answer: C
Reflection
Explanation: Light travels in a straight line. Reflection is one of the properties of light. And this is the property in which mirror make use of. The ability of light to bounce back. It's this bouncing back characteristics of light ray that eventually produce the image of an object by the mirror.
If the light ray is absorbed, no image will be produced.
Answer:
F = 22.75 lb
μ₁ = 0.15
Explanation:
The smallest force required to move the dresser must be equal to the force of friction between the man and the dresser. Therefore,
F = μR
F = μW
where,
F = Smallest force needed to move dresser = ?
μ = coefficient of static friction = 0.25
W = Weight of dresser = 91 lb
Therefore,
F = (0.25)(91 lb)
<u>F = 22.75 lb</u>
<u></u>
Now, for the coefficient of static friction between shoes and floor, we use the same formula but with the mas of the man:
F = μ₁W₁
where,
μ₁ = coefficient of static friction between shoes and floor
W₁ = Weight of man = 151 lb
Therefore,
22.75 lb = μ₁ (151 lb)
μ₁ = 22.75 lb/151 lb
<u>μ₁ = 0.15</u>
