Answer:
f = 692 N
Explanation:
given data:
f =800N
a =1.2 m s^{2}
m= 90 kg
from newton's second law
net force 
therefore we have from above equation
ma =F - f
putting all value to get force of friction
1.2*90 = 800 - f
f = 692 N
Answer:
c = 5 m
Explanation:
this exercise you want to divide the rectangular room into two triangular rooms
the area of triangles is
A = ½ base height
A = ½ 4 3
A = 6 m²
the length of the curtain can be found using the Pythagorean theorem
c² = b² + a²
c = √ (4² + 3²)
c = 5 m
this is the length of the curtain
Answer:

Explanation:
For the cat to stay in place on the merry go round without sliding the magnitude of maximum static friction must be equal to magnitude of centripetal force

Where the r is the radius of merry-go-round and v is the tangential speed
but

So we have

Substitute the given values
So

Answer:
14.36 N
Explanation:
= Tension in string 1
= Tension in string 2
= mass of the bar = 2.7 kg
= weight of the bar
weight of the bar is given as
N
= mass of the bar = 1.35 kg
= weight of the monkey
weight of the monkey is given as
N
Using equilibrium of torque about left end
N
Using equilibrium of force in vertical direction
N