Answer:
A) Increases by a factor of 2
Explanation:
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Given that mass, m = 2m
Substituting into the equation, we have;
K.E = ½mv²
K.E = ½*2mv²
Cross-multiplying, we have;
2K.E = 2mv²
Hence, if the mass of an object increases by a factor 2, kinetic energy is increased by a factor of 2.
Answer: 14.28 m/s
Explanation:
Assuming the girl is spinning with <u>uniform circular motion</u>, her centripetal acceleration is given by the following equation:
(1)
Where:
is the <u>centripetal acceleration</u>
is the<u> tangential speed</u>
is the <u>radius</u> of the circle
Isolating from (1):
(2)
<u />
Finally:
This is the girl's tangential speed
Answer:
Explanation:
This question assumes uniformly accelerated motion, for which the distance d a particle travels in time t is given by the general equation:
That is a quadratic equation, where the independent variable is the time .
Thus, the procedure that will find the time t at which the distance value is known to be D is to solve the quadratic equation for .
To solve it you start by changing the equation to the general form of the quadratic equations, rearranging the terms:
Some times that equation may be solved by factoring, and always it can be solved by using the quadratic formula:
Where:
That may have two solutions. Some times one of the solution makes no physical sense (for example time cannot be negative) but others the two solutions are valid.