1) At the moment of being at the top, the piston will not only tend to push the penny up but will also descend at a faster rate at which the penny can reach in 'free fall', in that short distance. Therefore, at the highest point, the penny will lose contact with the piston. Therefore the correct answer is C.
2) To solve this problem we will apply the equations related to the simple harmonic movement, hence we have that the acceleration can be defined as

Where,
a = Acceleration
A = Amplitude
= Angular velocity
From a reference system in which the downward acceleration is negative due to the force of gravity we will have to



From the definition of frequency and angular velocity we have to




Therefore the maximum frequency for which the penny just barely remains in place for the full cycle is 2.5Hz
Answer:
D: The side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole
Explanation:
D: The side of Magnet A that's attracted to Magnet B's south pole must be Magnet A's north pole because
1) opposite poles attract each other
2) similar poles repel each other
3)magnetic lines of force start at the north pole and end at the south pole
Answer:
7.72 Liters
Explanation:
normal body temperature = T_body =37° C
temperature of ice water = T_ice =0°c
specfic heat of water = c_{water} =4186J/kg.°C
if the person drink 1 liter of cold water mass of water is = m = 1.0kg
heat lost by body is Qwater =mc_{water} ΔT
= mc{water} ( T_ice - T_body)
= 1.0×4186× (0 -37)
= -154.882 ×10^3 J
here negative sign indicates the energy lost by body in metabolic process energy expended due to brisk - hour long walk is Q_{walk} = 286 kilocalories
= 286×4186J
so number of liters of ice water have to drink is
n×Q_{water} =Q_{walk} n= Q_{walk}/ Q_{water}
= 286×4186J/154.882×10^3 J
= 7.72 Liters
It’s not Cereal and Milk, carbonated drinks, and smoky air
Answer:
The magnitude of the hiker’s displacement is 2.96 km
Explanation:
Let the initial displacement of the hiker, = x = 2km
the final displacement of the hiker, = y = 1.4 km
The resultant of the two vectors, According to Pythagorean theorem is the vector sum of the two vectors.
R' = x' + y'
Check the image uploaded for solution;