Answer: constructive interference
Explanation: plz mark Brainly
1. lifts it chest high
The force opposing to this action is the force due to
gravity. Therefore the work done is:
W1 = m g d
where m is mass of the barbell, g is gravity and d is displacement
2. holds it for 30 seconds
Work is a product of force and displacement, since there
is no displacement, therefore work done is zero.
W2 = 0
3. puts it down slowly
If the barbell was dropped, then it would simply be a free
fall. But since it was not, so the work done here is also equal to the weight
of the barbell times displacement:
W3 = m g d
We can see that W1 = W3, and since W2 = 0, therefore the answer
is:
<span>w3 = w1 > w2</span>
Answer:
2.77 * 10^5 m/s
Explanation:
Let us recall that kinetic energy is given by 1/2 mv^2
Where;
m = mass of the body
v = velocity of the body
In this case,
m = 3.38 * 10^31 kg
KE= 1.30 * 10^42 J
KE = 1/2 mv^2
v = √2KE/m
v = √2 * 1.30 * 10^42/3.38 * 10^31
v = √7.69 * 10^10
v = 2.77 * 10^5 m/s
True . this is called a complex substance
