Answer:
a)15 N
b)12.6 N
Explanation:
Given that
Weight of block (wt)= 21 N
μs = 0.80 and μk = 0.60
We know that
Maximum value of static friction given as
Frs = μs m g = μs .wt
by putting the values
Frs= 0.8 x 21 = 16.8 N
Value of kinetic friction
Frk= μk m g = μk .wt
By putting the values
Frk= 0.6 x 21 = 12.6 N
a)
When T = 15 N
Static friction Frs= 16.8 N
Here the value of static friction is more than tension T .It means that block will not move and the value of friction force will be equal to the tension force.
Friction force = 15 N
b)
When T= 35 N
Here value of tension force is more than maximum value of static friction that is why block will move .We know that when body is in motion then kinetic friction will act on the body.so the value of friction force in this case will be 12.6 N
Friction force = 12.6 N
Answer:
As an object moves faster, its mass increases. ... Because masses approach infinity with increasing speed, it is impossible to accelerate a material object to (or past) the speed of light. To do so would require an infinite force.
3. Distance is a quantity that is always a vector.
B.
Answer:
The field losses a total of 55.814 litres of water in an hour.
Explanation:
As the complete question is not given here, the average rate of water loss is not given here which is found in normal conditions as 1.67 mL/m2.
Now the average rate of water loss per minute is 1.67 mL/m2
So the average rate of water loss per minute for 557 m2 is 1.67*557=930.19 mL
So 930.19 mL of water is lost from the field in 1 minute, for the calculation of water lost in an hour, the value is given as 60*930.19 =55811.4 mL or 55.814 litres.
