Answer:
a) 0.500 s
b) greater than 0.500 s
c) greater than 0.500 s
Explanation:
The time period of an oscillating spring-mass system is given by:

where, m is the mass and k is the spring constant.
a) As the period of oscillation does not depend on the distance by which the mass is pulled, the period would remain same as 0.500 s for the given system.
b) As the period varies inversely with the square root of spring constant, so with the decrease in the spring constant, the period would increase. So, the new period would be greater than 0.500 s.
c) As the period varies directly with the square root of mass, so with the increase in mass, the period will also increase. The new period will be greater than 0.500 s.
B.
The child is too old to be gaining something from the screen time.
Answer:
t = 25 seconds
Explanation:
Given that,
Distance, d = 115 m
Initial speed, u = 4.2 m/s
Final speed, v = 5 m/s
We need to find the time taken in increasing the speed.
We know that,
Acceleration,
....(1)
The third equation of kinematics is as follows :

Hence, it will take 25 seconds to increase the speed.
Answer:
We need to multiply 12 to each term to eliminate fractions.
Explanation:
Given expression:

To eliminate the fraction we need to multiply each term by least common multiple of the denominators of the fraction.
The denominators in the above expressions are:
4, 3 and 2
The multiples of each can be listed below.
2⇒ 2,4,6,8,10,<u>12</u>,14,16.....
3⇒ 3,6,9,<u>12</u>,15,18
4⇒ 4,8,<u>12</u>.......
From the list of the multiples stated, we can see the least common multiple is 12.
So we will multiply each term by 12.
Multiplying 12 to both sides.

Using distribution,

Thus we successfully eliminated the fractions.
Answer: option <span>A) a train moving north of east at an angle of 25°
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Explanation:
1) You need to choose your axis. In this case North is vertical and positive, South is vertical and negative, East is horizontal and positive, and West is horizontal and negative.
2) The vector with the two positive components is a vector in the first quadrant (North and East). That is what North of East 25° means.
3) Regarding the other options:
<span>B) a bus moving North of East at an angle of 95°: since the angle is greater tnan 90° the vector is in the second quadrant: its horizontal component is negative.
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C) a boat moving South of West at an angle of 40°: this is in the third quadrant: the two components are negative.</span>
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D) a car moving south of west at an angle of 10°: as in the option C), this is in the third quadrant: the two components are negative.
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