Answer:
160N
Explanation: When 80kg mass is one group . It's reaction force acting on a ground.
Weight of the object = 80*10
= 800 N
Here we are given cofficient of static friction its 0.2. It should be smaller than 1
Friction force = Reaction * Friction Cofficient
Reaction = 800N ( Considering Vertical Equilibrium )
F = 800* 0.2
F = 160N
Answer:
(A) 10052.2 m/s²
(B) 0.00678 seconds
Explanation:
From the question,
(A) Applying
V² = U²+2as..................... Equation 1
Where V = Final velocity, U = Initial velocity, a = acceleration due to gravity, s = distance.
make a the subject of the equation
a = (V²-U²)/2s........................ Equation 2
Given: U = 0 m/s( from rest), V = 68 m/s, s = 0.230 m
Substitute these values into equation 2
a = (68²-0²)/(2×0.230)
a = 10052.2 m/s²
(B) Using,
a = (V-U)/t......................... Equation 3
Where t= time.
make t the subject of the equation
t = (V-U)/a......................... Equation 4
Given: V = 68 m/s, U = 0 m/s, a = 10052.2
Substitute into equation 4
t = (68-0)/10052.2
t = 0.00678 seconds
Convection is the transfer of heat through a fluid
Conduction is the heat or electric current from one substance to another
Radiation is energy that radiated or transmitted
Ex: Convection- A pot of water is being boiled- the heat is being transferred to to the water
Ex2: Conduction- I have a plate filled with hot food- the heat from the food is being transferred to the plate, making the plate hot as well.
Ex3: Radiation- There is a dog by the fire place, the dog is being warmed- the heat from the fire is being transferred over to the dog
Hope this will help you with your homework :)
Answer:
Explanation:
y_1 = (3 mm) sin(x - 3t)
comparing it with standard wave equation
y = A sin( ωt-kx )
we see
ω = -3 , k = -1
velocity = ω / k
= 3
y_2 = (6 mm) sin(2x - t)
we see
ω = -1 , k = -2
velocity = ω / k
= .5
y_3 = (1 mm) sin(4x - t)
we see
ω = -1 , k = -4
velocity = ω / k
= .25
y_4 = (2 mm) sin(x - 2t)
we see
ω = -2 , k = -1
velocity = ω / k
= 2
So greatest velocity to lowest velocity
y_1 = (3 mm) sin(x - 3t) , y_4 = (2 mm) sin(x - 2t) ,y_2 = (6 mm) sin(2x - t) , y_3 = (1 mm) sin(4x - t)
b )
Given the mass per unit length of wire the same , velocity is proportional to
√ T , where T is tension
so in respect of tension in the wire same order will exist for highest to lowest tension .
Answer:
The kinetic energy gained is 40[J]
Explanation:
This is a problem that applies the work and energy conservation. We must analyze the initial and final positions as well as the forces that act on the couch during displacement.
The working and energy conservation theorem says:

The above equation tells us that kinetic energy plus the work done to move an object from one position to another will be equal to kinetic energy in the last position.
The kinetic energy in the initial position is zero since the couch is at rest, Ek1=0
The work will be given by the force that drives the couch multiplied by the distance, and the friction force that acts in the opposite direction to the displacement.
![0+(200-180)*2= Ek2\\Ek2=20*2= 40 [J]](https://tex.z-dn.net/?f=0%2B%28200-180%29%2A2%3D%20Ek2%5C%5CEk2%3D20%2A2%3D%2040%20%5BJ%5D)