Solution:
We have,
Power [P] = 25000 Watt
Mass [m] = 6000 kg
Height [h] = 20 metres
Time [t] = ?
Now,
P = W/t = F x d/t = mxgx h/t
Or, 25000 = 6000 x 10 x 20/25000 [.......g = 10
m/s^2]
Or, t = 6000 x 10 x 20/25000
Or, t = 1200/25
Therefore, t = 48 second
Hence, the required time for the crane to lift the load is 48 seconds.
<span>The magnitude of the gravitational force between two bodies is the product of their masses divided by the square of the distance between them. So we have F = M1*M2 / r^2. M1 = 7.503 * 10e24 and M2 = 2.703 * 10e22 and r= 2.803 * 10e8; r^2 = 5.606 *10e16. So we have 7.503 *2.703 *10^(24+22) = 20.280 * 10^(46). Then we divide our answer by 5.606 * 10e16 which is the distance ; then we have 3.6175 * 10 e (46- 16) = 3.6175 * 10e30.
To find the acceleration we use Newton's second law F = ma. F is 3.6175 * 10e30 and M is 7.503 * 10e24 so a = F/M and then we have 3.6175/7.503 * 10e (30-24) = 0.48 * 10e6.
Similarly for moon, we have a = 3.6715/2.703 * 10e(30-22). = 1.358 * 10e8</span>
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
Answer:
A) True, B) False, C) False and D) false
Explanation:
Let's solve the problem using the law of conservation of energy to know if the statements are true or false
Let's look for mechanical energy
Initial
Emo = Ke = ½ k Dx2
Final
Em1= ½ m v12
Emo = Em1
½ k Δx2 = ½ m v₁²
v₁² = k / m Δx²
v₁ = √ k/m Δx
Now let's calculate the speed when it falls
Vfy² = Voy² - 2gy
Vfy² = - 2gy
Vf² = v₁² + vfy²
A) True v₁ = A Δx
.B) False. As there is no rubbing the mechanical energy conserves
.C) False the velocity is proportional to the square root of the height
v2y = v2 √2
. D) false promotional compression speed
I would think the answer is c.
