Answer:
The correct answer is "22.27 hours".
Explanation:
Given that:
Radioactive isotope activity,
= 490,000 Bq
Activity,
= 110,000 Bq
Time,
= 48 hours
As we know,
⇒ 
or,
⇒ 
By taking "ln", we get
⇒ 
By substituting the values, we get
⇒ 
⇒ 
As,
⇒ 
then,
⇒ 
⇒ 
Answer:
A quantity that has magnitude and direction. It's usually represented by an arrow whose direction is the same direction is the same as that of the quantity and whose length is proportional to the quantity's magnitude
Answer: 210.2N
Explanation:
Assume a bucket of water with a total mass of 68kg is attached to a rope, which in turn is tied around a 0.078m radius cylinder at the top of a well. A crank with a turning radius of 0.250 m is attached to the end of the cylinder.
the minimum force directed perpendicular to the crank handle required to raise the bucket is
(Assume the rope's mass is negligible, that the cylinder turns on friction-less bearings, and that g = 9.8 m/s2
The crank handle provides a torque T=0.25F where F is the force we are looking for.
A free body diagram will show that the tension in the rope times the cylinder radius R is equal to the torque on the cylinder. But the tension in the rope is just the weight of the bucket
W=mg= 68kg
W(0.078)=T=0.25F
F=0.312W=0.312(68kg)=21.216kg= 210.2N
Factors Affecting the Rate of Erosion<span>. The biggest factor affecting coastal </span>erosion<span> is the </span>strength<span> of the waves breaking along the coastline. A wave's </span>strength<span> is controlled by its fetch and the </span>wind speed<span>.</span>
