Answer:
K = 960 J
Explanation:
Given that,
Mass of a child = 20 kg
Mass of a sled = 10 kg
Speed of child on sled = 8 m/s
We need to find the kinetic energy of the sled with the child.
The total mass of child and the sled = 20 kg + 10 kg
= 30 kg
The formula for the kinetic energy of an object is given by :
Hence, the kinetic energy of the sled with the child is 960 J.
A. overgrazing of livestock
Explanation:
Overgrazing of livestock is the ranch practice that contributes to soil erosion.
Soil erosion is the washing away of the top layer of the earth on which plant grows.
- Plants are covers of the earth and they prevent agents of denudation from actively washing away the soil.
- When livestock are introduced into a place, continuous grazing leaves the surface bare.
- The plants becomes depleted and the surface is exposed.
- This fast tracks the process of overgrazing.
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Soil erosion brainly.com/question/2473244
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Answer:
Angular acceleration, is 
Explanation:
Given that,
Initial speed of the drill, 
After 4.28 s of constant angular acceleration it turns at a rate of 28940 rev/min, final angular speed, 
We need to find the drill’s angular acceleration. It is given by the rate of change of angular velocity.
So, the drill's angular acceleration is .
Answer:
1) λ = 0.413 m
, 2)v = 25,213 m / s
, 3) T = 0.216 N
, 4) m = 22.04 10-3 kg
Explanation:
1) The resonance occurs when the traveling wave bounces at the ends and the two waves are added, the ends as they are fixed have a node, the wavelength and the length of the string are related
λ = 2L / n n = 1, 2, 3 ...
In this case L = 0.62 m and n = 3
Let's calculate
λ = 2 0.62 / 3
λ = 0.413 m
2) the velocity related to wavelength and frequency
v = λ f
v = 0.413 61
v = 25,213 m / s
3) let's use the equation
v = √T /μ
T = v² μ
T = 25,213² 3.4 10⁻⁴
T = 0.216 N
4) the rope tension is proportional to the hanging weight
T-W = 0
T = W
W = m g
m = W / g
m = 0.216 / 9.8
m = 22.04 10-3 kg
5) n = 2
λ = 2 0.62 / 2
λ = 0.62 m
6) v = λ f
v = 0.62 61
v = 37.82 m / s
7) T = v² μ
T = 37.82² 3.4 10⁻⁴
T = 0.486 N
8) m = W / g
m = 0.486 / 9.8
m = 49.62 10⁻³ kg
9) n = 1
λ = 2 0.62
λ = 1.24 m
v = 1.24 61
v = 75.64 m / s
T = v² miu
T = 75.64² 3.4 10⁻⁴
T = 2.572 10⁻² N
m = 2.572 10⁻² / 9.8
m = 262.4 10⁻³ kg
