<em>Quantities that determine the kinetic energy of a body are its </em><em>mass and velocity </em>
Answer: <em>mass and velocity </em>
Explanation:
The kinetic energy of a body is the energy possessed by an object by virtue of its motion. It is given by the equation
Where m represents mass of the body and v represents its velocity.
Two bodies of equal velocity but different mass the heavier body will have greater kinetic energy. When an object is at rest its velocity is equal to zero. Thus its kinetic energy will be zero. Hence it can be concluded that only moving bodies have kinetic energy.
Stationary objects placed at a height possess potential energy which is the energy by virtue of their position or configuration. The total mechanical energy of a system is the sum of potential and kinetic energy.
Answer:
b
Explanation:
friction needs two objects
the two objects need to touch each other
the two objects need to either have relative movement or, tend to have relative movement urge. (kinetic friction or static friction)
Answer:
The time rate of change in air density during expiration is 0.01003kg/m³-s
Explanation:
Given that,
Lung total capacity V = 6000mL = 6 × 10⁻³m³
Air density p = 1.225kg/m³
diameter of the trachea is 18mm = 0.018m
Velocity v = 20cm/s = 0.20m/s
dv /dt = -100mL/s (volume rate decrease)
= 10⁻⁴m³/s
Area for trachea =
0 - p × Area for trachea =
⇒
ds/dt = 0.01003kg/m³-s
Thus, the time rate of change in air density during expiration is 0.01003kg/m³-s
Answer:
a) x = 8.8 cm * cos (9.52 rad/s * t)
b) x = 8.45 cm
Explanation:
This is a Simple Harmonic Motion, and most Simple Harmonic Motion equations start from the equilibrium point. In this question however, we are starting from the max displacement the equations, and thus, it ought to be different.
From the question, we are given that
A = 8.8 cm = 0.088 m
t = 0.66 s
Now, we need to find the angular speed w, such that
w = 2π/T
w = (2 * 3.142) / 0.66
w = 6.284 / 0.66
w = 9.52 rad/s
The displacement equation of Simple Harmonic Motion is usually given as
x = A*sin(w*t)
But then, the equation starts from the equilibrium point at 0 sec, i.e x = 0 m
When you have to start from the max displacement, then the equation would be
x = A*cos(w*t).
So when t = 0 the cos(0) = 1, and then x = A which is max displacement.
Thus, the equation is
x = 8.8 cm * cos (9.52 rad/s * t)
At t = 1.7 s,
x = 8.8 cos (9.52 * 1.7)
x = 8.8 cos (16.184)
x = -8.45 cm
Answer: The correct answer is C.
2/10 is simplified to 1/5, that is the factor that changes.