<span>Cobalt-60 is undergoing a radioactivity decay.
The formula of the decay is n=N(1/2)</span>∧(T/t).
<span>Where N </span>⇒ original mass of cobalt
<span> n </span>⇒ remaining mass of cobalt after 3 years
T ⇒ decaying period
t ⇒ half-life of cobalt.
So,
0.675 = 1 × 0.5∧(3/t)
log 0.675 = log 0.5∧(3/t)
3/t = log 0.675 ÷log 0.5
3/t= 0.567
t = 3÷0.567
= 5.290626524
the half-life of Cobalt-60 is 5.29 years.
<span>
</span><span>
</span>
Answer:43.34 m
Explanation:
Given
acceleration(a)
Initial Velocity(u)=0 m/s
After 6 s fuel runs out
Velocity after 6 s
v=u+at

After this object will start moving under gravity
height reached in first 6 s


s=36 m
After fuel run out distance traveled in upward direction is

here v=0
u=12 m/s




<h3>Option B</h3><h3>The time constant of a 10 H inductor and a 200 ohm resistor connected in series is 50 millisecond</h3>
<em><u>Solution:</u></em>
Given that,
10 H inductor and a 200 ohm resistor connected in series
To find: time constant
<em><u>The time constant in seconds is given as:</u></em>

Where,
L is the inductance in henry and R is the resistance in ohms

Convert to millisecond
1 second = 1000 millisecond
0.05 second = 0.05 x 1000 = 50 millisecond
Thus time constant is 50 millisecond
Answer:
False.
Explanation:
Mechanical waves require a medium in order to transport their energy from one location to another.
As per the third law of Newton, the force exerted by the boat over the student is equal in magnitude to the force that the student exerted on the boat.
So, calculate the force on the student using the second law of Newton, Force = mass * acceleration.
Force on the student = 60 kg * 2.0 m/s^2 = 120 N.
=> horizontal force exerted by the student on the boat = 120 N
Answer: option d. 120 N. toward the back of the boat.
Of course it is toward the back because that is where the student jumped from..