There are some missing data in the text of the problem. I've found them online:
a) coefficient of friction dry steel piston - steel cilinder: 0.3
b) coefficient of friction with oil in between the surfaces: 0.03
Solution:
a) The force F applied by the person (300 N) must be at least equal to the frictional force, given by:
where
is the coefficient of friction, while N is the normal force. So we have:
since we know that F=300 N and
, we can find N, the magnitude of the normal force:
b) The problem is identical to that of the first part; however, this time the coefficienct of friction is
due to the presence of the oil. Therefore, we have:
The answer is letter c.
The explanation behind this is when human consumes a plant
or when a human being eats an animal that ate a plant. The chemical energy kept
in the plant (or animal) cells is progressed into the cells of the human's
body. All of the body progressions, like ingestion, breathing, pumping blood, are
driven by cells changing the kept chemical energy into heat and work, in a procedure
called respiration. In the muscle cells of the human (or any animal), the
chemical energy is converted into mechanical work and heat. The muscle pacts,
the legs thrust, and the body jumps into the air.
Linear momentum is in a straight line and depends on the objects mass and velocity.
Angular (rotational) momentum depends on the objects mass, velocity, and radius.
Answer:
Total energy is 170 kJ
Explanation:
Given data:
latent heat of fusion of alcohol is 25 kcal/kg
melting point of alcohol is -114 degree c
specific heat us 0.60 k cal/kg degree c
energy need for 2 kg solid alcohol is
for Melting:
Energy Q is calculated as
Energy, Q = 25 \times 2.0 kg = 50 kJ
Energy required for Heating liquid:
Energy, ΔH = 2.0 kg \times 0.60 \times (100°C) = 120 kJ
Total energy = (50 kJ + 120 kJ) = 170 kJ
Answer:
B. counterclockwise
Explanation:
We shall apply Lenz's law to find direction of induced current . According to it , direction of induced current is such that the magnetic field produced by it will try to nullify the change in magnetic field that produces it. Increase in magnetic field in down ward direction is producing it so to nullify it , magnetic field induced will be in upward direction. For it current induced will be anticlockwise.
