Question

Дано:A=35КДж,cosA=60*,m=3кг найти L-?

Answer 1

A=F*L*cosA
F=m*g
A=m*g*L*cosA
L=A/mgcosA
L=35*10^3/3*10*0,5=2,3*10^3=2300м

Answer 2

To find L, we can use the formula for mechanical work:

W = F * d * cosθ

where: W is the work done (in joules or J), F is the force applied (in newtons or N), d is the distance moved in the direction of the force (in meters or m), θ (theta) is the angle between the force vector and the displacement vector (in degrees or degrees).

In this case, we are given: A = 35 kJ (kilojoules) = 35,000 J (joules) cosA = 60 degrees m = 3 kg (kilograms)

We need to find L, which is the distance (d).

Let's calculate it step by step:

Step 1: Convert A from kJ to J: A = 35 kJ = 35,000 J

Step 2: Calculate the work done (W) using the formula: W = A = 35,000 J

Step 3: Calculate the force (F) using the formula for mechanical work: W = F * d * cosθ

Since W = 35,000 J and cosA = 60 degrees, we can rearrange the formula to solve for F: F = W / (d * cosθ)

Step 4: Calculate the force (F) using the given mass (m) and acceleration due to gravity (g): F = m * g

where g is the acceleration due to gravity, which is approximately 9.81 m/s².

F = 3 kg * 9.81 m/s² = 29.43 N

Step 5: Equate the two expressions for force (F) and solve for d: m * g = W / (d * cosθ)

d * cosθ = W / (m * g)

d = W / (m * g * cosθ)

Step 6: Plug in the values and calculate d: d = 35,000 J / (3 kg * 9.81 m/s² * cos(60°)) d = 35,000 J / (3 kg * 9.81 m/s² * 0.5) d = 35,000 J / (14.715 N) d ≈ 2378.26 m

So, the value of L (the distance) is approximately 2378.26 meters.