Answer: B. Concrete
Explanation:
Let N = reacting force pressing the bodies in context together (units in Newtons),
The question stated that the force pressing the two mounted/stacked objects together is equal to the weight of the object on top.
We need to start by finding the weight of the piece of wood.
friction is given by
f = μN
The value of f is 22.5,
and from the chart reference the coefficient of friction between wood and stone, μ is 0.30.
22.5 = 75. 0.30
Putting the values into the equation: 22.5 = 0.30N.
Divide both sides by 0.30 to find the value of N:
N= 22.5/0.3 = 75
Now that the piece of wood will be placed on another surface, its weight of 75 Newton is the force pressing the two bodies together.
To determine the new surface, you should find the new coefficient of friction by using the new value of the force of friction given 46.5:
46.5 = µ(75).
Divide both sides by 75 to isolate μ.
The refer chart also indicates that the coefficient of friction equals 0.62 between wood and concrete, so the new surface corresponding to 0.62 is the concrete, which is (B).
Answer:
C) Unscrew one light. If the other lights turn off, it's a series circuit.
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
A strand of 10 lights is plugged into an outlet. How can you determine if the lights are connected in series or parallel? A) Unscrew one light. If the other lights stay on, it's a series circuit. B) Unplug the strand. If the first light stays on, it's a series circuit. C) Unscrew one light. If the other lights turn off, it's a series circuit. D) Cut the strand in half. If the plugged in half stays on, it's a series circuit.
SERIES CIRCUIT
In this circuit, the components there are in the same path, the entire circuit has the same current, each of the components posses different voltage drop. Hence, failure of one components to work, there will be break in entire circuit then other components cease to work.
PARALLEL CIRCUIT
This circuit has equal voltage drop across all the components, any problem in a component will not has effect on other components.
Therefore, if one want to determine if a light connection is in series or in parallel, one of the light can be unplugged if others stop working it means it's series, if other works it's parallel.
Answer:
29.38 seconds
Explanation:
Half life, T = 22.07 s
No = 1293
Let N be the number of atoms left after time t
N = 1293 - 779 = 514
By the use of law of radioactivity
Where, λ is the decay constant
λ = 0.6931 / T = 0.6931 / 22.07 = 0.0314 decay per second
so,
take natural log on both the sides
0.9225 = 0.0314 t
t = 29.38 seconds
Answer:
A. 20 N
Explanation:
the weight of book is 2×10= 20N
Answer:
m = 327.07 kg
Explanation:
Given that,
Kinetic energy of a motorcycle, E = 57800 J
Velocity of the motorcycle, v = 18.8 m/s
We need to find the mass of the motorcycle. The kinetic energy of an object is given by :
m is mass
So, the mass of the motorcycle is 327.07 kg.
