A protostar reaches equilibrium when gravity is balanced by the outward force of nuclear fusion.
Answer:
two places where thermal conduction takes place are gases and liquids, conduction is due to collisions of molecules during their random motion. Hence, the correct option is (C). Note: Though, the particle distances between gases are much more in comparison to solids and liquids, conduction slowly occurs in gases also
Explanation:
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Answer:
D. a person pulling a sled.
Explanation:
contact force only occurs when something directly comes in contact with another object.
a. is wrong because that is called magnetic force.
b. gravitational force
c. is an electrical force
A) the periodic time is given by the equation;
T= 2π√(L/g)
For the frequency will be obtained by 1/T (Hz)
T = 2 × 3.14 √ (0.66/9.81)
= 6.28 × √0.0673
= 1.6289 Seconds
Frequency = 1/T = f = 1/1.6289
thus; frequency = 0.614 Hz
b) The vertical distance, the height is given by
h= 0.66 cos 12
h = 0.65 m
Vertical fall at the lowest point = 0.66 - 0.65 = 0.01 m
Applying conservation of energy
energy lost (MgΔh) = KE gained (1/2mv²)
mgh = 1/2mv²
v² = 2gΔh = 2×9.81 × 0.01
= 0.1962
v = 0.443 m/s
c) total energy = KE + GPE = KE when GPE is equal to zero (at the lowest point possible)
Thus total energy is equal to;
E = 1/2mv²
= 1/2 × 0.310 × 0.443²
= 0.0304 J
Answer:
Pressure applied by the man= 285103.125
or 41.35 
Explanation:
Pressure is defined as the perpendicular force applied per unit area.
i.e. 
Now, 
where,
= mass of the body(man) = 93 kg
= acceleration due to gravity of Earth = 9.81 
covered is equal to the area of both stilts(a man generally stands on two feet)
therefore

and putting in the values, we get,

Now we need to convert to our required units:

(We can get the above result by individually converting kg to lb and meters to inches respectively)
Using the above relations we get,
