Answer:
a) U = 735 J
, b) U = 125.7 J
, c) U = 0 J
Explanation:
The gravitational power energy is
U = mg y - mg y₀
The last value is a constant, for simplicity we can make it zero, if the lowest point is at the origin of the coordinate system, which in this case we will place in the lowest part
a) Rope is horizontal
The height in this case is the same length of the rope
y = 2.10 m
w = mg = 350 N
U = 350 2.10
U = 735 J
b) when the angle is 34º
y = L - L cos 34
y = L (1- cos34)
y = 2.10 (1- cos 34)
y = 0.359 m
U = 350 0.359
U = 125.7 J
c) in this case this point coincides with the reference system
y = 0
U = 0 J
Answer:
33.6 Ns backward.
Explanation:
Impulse: This can be defined as the product of force and time. The S.I unit of impulse is Ns.
From Newton's second law of motion,
Impulse = change in momentum
I = mΔv................................. Equation 1
Where I = impulse, m = mass of the skater, Δv = change in velocity = final velocity - initial velocity.
Given: m = 28 kg, t = 0.8 s, Δv = -1.2-0 = -1.2 m/s (Note: the initial velocity of the skater = 0 m/s)
Substituting into equation 1
I = 28(-1.2)
I = -33.6 Ns
Thus the impulse = 33.6 Ns backward.
Speed is the rate of change <span>of distance.</span>
The total distance is 70km.
The total time is 60 minutes or 1 hour.
Speed=Distance÷Time
=70÷1
=70km/h
Answer:
Option B. 8.1
Explanation:
From the question given above, the following data were obtained:
Angle θ = 71°
Hypothenus = 25
Adjacent = x
Thus, we can obtain the x component of the vector by using the cosine ratio as illustrated below:
Cos θ = Adjacent /Hypothenus
Cos 71 = x/25
Cross multiply
x = 25 × Cos 71
x = 25 × 0.3256
x = 8.1
Therefore, the x component of the vector is 8.1
