Answer:
Explanation:
When the box is on the ramp , component of its weight along the ramp
= mg sinθ
Friction force acting on it in upward direction
=μ mg cosθ
For sliding
μ mg cosθ < mg sinθ
μ cosθ < sinθ
.5 x cos35 < sin35
.41 < .57
So the box will slide
When sliding starts , kinetic friction acts
Net force in downward direction
mgsinθ - μ mg cosθ
acceleration
= gsinθ - μ g cosθ
= 5.62 - .3 x 9.8 x cos35
= 5.62 - 2.4
= 3.22 m /s²
A. Upstream refers to the motion of the swimmer where he is against the current. The resultant speed of the swimmer is equal to the difference of the velocity or speed in still water and that of the river. The time it requires to cover the distance is calculated through the equation,
t = d / s
where t is time, d is distance, and s is speed. Substituting the known values,
t = 1000 m / (1.2 m/s - 0.5 m/s) = 1,428.57 seconds
(b) The time it requires for the swimmer to swim in still water,
t = 1000 m / (1.2 m/s) = 833.33 seconds
(c) Intuitively, it takes longer to cover the distance when there is current because the current will serve as resistance to the motion of the swimmer, partially moving it backwards instead of forward.
θ = angle of the incline surface from the horizontal surface = 25⁰
μ = Coefficient of friction = 0.15
m = mass of the person = 65 kg
= kinetic frictional force acting on the person as he slides down
mg = weight of the person acting in down direction
= normal force by the incline surface on the person
the free body diagram showing the forces acting on the person is given as
Answer:
relay switch
Explanation:
relay switch is the answer