Answer:
(A) 60 J
Explanation:
At state 1
KE₁=100 J
At state 2
KE₂ = 0
U₂=80 J
Given that surface is rough so friction force will act in opposite to the direction of motion
Lets take work done by friction = Wfr
From work power energy
Work done by all forces = Change in kinetic energy
Wfr + U₂=ΔKE
Wfr+80 = 100
Wfr= 20 J
Now when book slides from top position then
Wfr+ U = KEf - KEi
-20 + 80 = KEf-0
KEf= 60 J
(A) 60 J
Answer:
Total height (s) = 176.4 m
Explanation:
Given:
Initial velocity (u) = 0 m/s
Time taken (t) = 6 sec
Acceleration due to gravity = 9.8 m/s²
Find:
Total height (s)
Computation:
s = ut + [1/2]gt²
s = (0)(6) + [1/2][9.8][6²]
s = 176.4 m
Total height (s) = 176.4 m
Using Newton's Second Law, F = ma, where F is the net force
So the net force is:
F = (6kg)(4m/s^2) = 24N
Since you are applying a horizontal force of 30N, we can find the force of friction by the difference of the net force and the applied force.
30N-24N = 6N
Answer:
option B
Explanation:
given,
Force exerted by the hydraulic jack piston = F₁ = 250 N
diameter of piston, d₁ = 0.02 m
r₁ = 0.01 m
diameter of second piston, d₂ = 0.15 m
r₂ = 0.075 m
mass of the jack to lift = ?
now,




F₂ = 14062.5 N
F = m g


m = 1435 Kg
hence, the correct answer is option B