The law of floatation states that, a floating body displaces its own weight of the fluid in which it floats.
Because it records speed of the car at a certain time, the independent variable should be time and dependent would be speed or velocity. Since it's taken every second, it would be considered instantaneous velocity, which is D.
Answer:
b) N = 560 N, c) fr = 138.56 N, d) μ = 0.247
Explanation:
a) In the attachment we can see the free body diagram of the system
b) Let's write Newton's second law on the y-axis
N + T_y -W = 0
N = W -T_y
let's use trigonometry for tension
sin θ = T_y / T
cos θ = Tₓ / T
T_y = T sin θ
Tₓ = T cos θ
we substitute
N = W - T sin 30
we calculate
N = 640 - 160 sin 30
N = 560 N
c) as the system goes at constant speed the acceleration is zero
X axis
Tₓ - fr = 0
Tₓ = fr
we substitute and calculate
fr = 160 cos 30
fr = 138.56 N
d) the friction force has the formula
fr = μ N
μ = fr / N
we calculate
μ = 138.56 / 560
μ = 0.247
A positive way that Friction helps in your every day life would be when you drive to work or school. There is friction acting upon your tires, without it you would continue to constantly move forwards until you have struck something, bringing you to a halt. Therefore friction is a positive in this case, however friction can also be a negative in your everyday life. This is possible because friction can be used against you, say you were dragging a box from point A to point B up a hill. You must use mechanical energy however going uphill already presents a problem, now if the wind were to blow you would be moving against friction, this is a negative.
