Refer to the diagram shown below.
m = the mass of the object
x = the distance of the object from the equilibrium position at time t.
v = the velocity of the object at time t
a = the acceleration of the object at time t
A = the amplitude ( the maximum distance) of the mass from the equilibrium
position
The oscillatory motion of the object (without damping) is given by
x(t) = A sin(ωt)
where
ω = the circular frequency of the motion
T = the period of the motion so that ω = (2π)/T
The velocity and acceleration are respectively
v(t) = ωA cos(ωt)
a(t) = -ω²A sin(ωt)
In the equilibrium position,
x is zero;
v is maximum;
a is zero.
At the farthest distance (A) from the equilibrium position,
x is maximum;
v is zero;
a is zero.
In the graphs shown, it is assumed (for illustrative purposes) that
A = 1 and T = 1.
Answer: • using beaker tongs to handle the hot beaker.
• checking the beaker for chips prior to heating on the hot plate.
• Turning off the hot plate after use
Explanation:
The options that will ensure laboratory safety during the experiment will be:
• using beaker tongs to handle the hot beaker.
• checking the beaker for chips prior to heating on the hot plate.
• Turning off the hot plate after use.
We should note that the beaker tongs are simply used in the holding of the beakers that have hot liquids in them. Also, it s vital for the hot plate to be turned off after its use so as to prevent accident.
ANSWER:
3408.81 kg
STEP-BY-STEP EXPLANATION:
Given:
v = 111 m/s
Ek = 21000000 J
We have that the formula for kinetic energy is as follows:

We substitute the values given in the exercise and solve for m (mass)

The mass of the helicopter is 3408.81 kilograms.