Answer:
W = 30 J
Explanation:
given,
Work done = 10 J
Stretch of spring, x = 0.1 m
We know,
dW = F .dx
we know, F = k x


![W = k[\dfrac{x^2}{2}]_0^{0.1}](https://tex.z-dn.net/?f=W%20%3D%20k%5B%5Cdfrac%7Bx%5E2%7D%7B2%7D%5D_0%5E%7B0.1%7D)

k = 2000
now, calculating Work done by the spring when it stretched to 0.2 m from 0.1 m.

![W = 2000 [\dfrac{x^2}{2}]_{0.1}^{0.2} dx](https://tex.z-dn.net/?f=W%20%3D%202000%20%5B%5Cdfrac%7Bx%5E2%7D%7B2%7D%5D_%7B0.1%7D%5E%7B0.2%7D%20dx)
W = 1000 x 0.03
W = 30 J
Hence, work done is equal to 30 J.
Answer:
Explanation:
mass of backpack, m = 8.1 kg
weight of climber, W = 656 N
height raised, h = 9.4 m
time, t = 28.2 min = 28.2 x 60 = 1692 second
weight of backpack, w = m x g = 8.1 x 9.8 = 79.38 N
Work done by the climber on the backpack = mg x h = 79.38 x 9.4 = 746.17 J
Wok done in lifting herself + backpack = (W + w) x h
= (656 + 79.38) x 9.4 = 6912.57 J
Power developed by the climber,P = Total work / time
P = 6912.57 / 1692 = 4.09 W
Answer:
θ = 12.60°
Explanation:
In order to calculate the angle below the horizontal for the velocity of the hockey puck, you need to calculate both x and y component of the velocity of the puck, and also you need to use the following formula:
(1)
θ: angle below he horizontal
vy: y component of the velocity just after the puck hits the ground
vx: x component of the velocity
The x component of the velocity is constant in the complete trajectory and is calculated by using the following formula:

vo: initial velocity = 28.0 m/s
The y component is calculated with the following equation:
(2)
voy: vertical component of the initial velocity = 0m/s
g: gravitational acceleration = 9.8 m/s^2
y: height
You solve the equation (2) for vy and replace the values of the parameters:

Finally, you use the equation (1) to find the angle:

The angle below the horizontal is 12.60°
Answer:
Velocidad final, V = 8 m/s
Explanation:
Dados los siguientes datos;
Velocidad inicial, u = 4 m/s
Aceleración, a = 2 m/s²
Tiempo, t = 2 segundos
Para encontrar la velocidad final (v), usaríamos la primera ecuación de movimiento;
V = u + at
Sustituyendo en la fórmula, tenemos;
V = 4 + 2*2
V = 4 + 4
Velocidad final, V = 8 m/s