How much work does it take to lift 345 boxes to a height of 6.00 m of each box has a mass of 7.89 kg
1 answer:
You might be interested in
Answer:
v=12.5 i + 12.5 j m/s
Explanation:
Given that
m₁=m₂ = m
m₃ = 2 m
Given that speed of the two pieces
u₁=- 25 j m/s
u₂ =- 25 i m/s
Lets take the speed of the third mass = v m/s
From linear momentum conservation
Pi= Pf
0 = m₁u₁+m₂u₂ + m₃ v
0 = -25 j m - 25 i m + 2 m v
2 v=25 j + 25 i m/s
v=12.5 i + 12.5 j m/s
Therefore the speed of the third mass will be v=12.5 i + 12.5 j m/s
<h2>Hello!</h2>
The answer is: B. Kinetic energy
<h2>Why?</h2>Since the ball is falling, speed increases because the gravity acceleration is acting. When speed increases, the kinetic energy increases too, so the ball is gaining kinetic energy.
The gravity acceleration is equal to , it means that when falling, the ball will increase it's speed 9.81m every second.
We can calculate the kinetic energy by using the following formula:
Where:
Have a nice day!
<h2 />Answer:
c. V = 2 m/s
Explanation:
Using the conservation of energy:
so:
Mgh =
where M is the mass, g the gravity, h the altitude, I the moment of inertia of the pulley, W the angular velocity of the pulley and V the velocity of the mass.
Also we know that:
V = WR
Where R is the radius of the disk, so:
W = V/R
Also, the moment of inertia of the disk is equal to:
I =
I =
I = 10 kg*m^2
so, we can write the initial equation as:
Mgh =
Replacing the data:
(5kg)(9.8)(0.3m) =
solving for V:
(5kg)(9.8)(0.3m) =
V = 2 m/s