Answer:
See the answers below.
Explanation:
We can solve both problems using Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F =m*a
where:
F = force [N] (units of newtons)
m = mass = 1000 [kg]
a = acceleration = 3 [m/s²]
![F = 1000*3\\F=3000[N]](https://tex.z-dn.net/?f=F%20%3D%201000%2A3%5C%5CF%3D3000%5BN%5D)
And the weight of any body can be calculated by means of the mass product by gravitational acceleration.
![W=m*g\\W=1000*9.81\\W=9810 [N]](https://tex.z-dn.net/?f=W%3Dm%2Ag%5C%5CW%3D1000%2A9.81%5C%5CW%3D9810%20%5BN%5D)
Answer:
The answer to this question is given below in this explanation section.
Explanation:
" law of conservation of energy"
The law of conservation of energy states that energy can neither be created nor destroyed only converted from one form of energy into another.This mean that a system always has a same account of a energy,unless it is added from the outside.This is particularly confusing in the case of non conversation forces,where energy is converted from ,mechanical energy into thermal energy.but the overall energy does remain the same.The only way to use energy is to transform energy from one form to another.
The amount of energy in any system than it is determined by the following equation.
Ut=Ui +W+Q
- Ut is the total internal energy of a system.
- Ui is the initial internal energy of a system.
- W is the work done by or on the system.
- Q is the heat added to or removed by the system.
It is also possible to determined the change in internal energy of the system using the equation.
ΔU=W+Q
The mechanical energy of a system increases provided their is no loss of energy due to friction.The energy would transform to kinetic energy when the speed is increasing.Te mechanical energy of a system remain constant provided their is no loss of energy due to friction.
The law of conversation of energy which say that in a closed system total energy is conserved that is it constant.
KE1 + PE1=KE2+PE2
Answer:
r₂ = 0.2 m
Explanation:
given,
distance = 20 m
sound of average whisper = 30 dB
distance moved closer = ?
new frequency = 80 dB
using formula

I₀ = 10⁻¹² W/m²
now,



to hear the whisper sound = 80 dB



we know intensity of sound is inversely proportional to square of distances



r₂ = 0.2 m
Answer:
2.4 m
Explanation:
Consider the motion along the vertical direction
= initial position of ball above the ground = 4.5 m
= time taken by the ball to hit the smokestack = 0.65 s
= initial velocity of the ball along vertical direction
= acceleration due to gravity = - 9.8 m/s²
= position of ball at the time of hitting the smokestack
Using the kinematics equation

inserting the above values
