Answer: 2.5 seconds
Explanation:
We know that the acceleration is:
a(t) = 1.7 m/s^2
To get the velocity function, we must integrate over time, and we will get:
v(t) = (1.7m/s^2)*t + v0
Where v0 is the initial velocity, in this case, we assume that we start at 23.6m/s, then the initial velocity is:
v0 = 23.6 m/s
Then the velocity equation is:
v(t) = (1.7m/s^2)*t + 23.6 m/s
Now we want to find the value of t such v(t) = 27.8 m/s
Then:
v(t) = 27.8 m/s = (1.7m/s^2)*t + 23.6 m/s
27.8 m/s - 23.6 m/s = (1.7m/s^2)*t
4.2 m/s = (1.7m/s^2)*t
4.2m/s/(1.7m/s^2) = t = 2.5 s
Then at that acceleration, you need 2.5 seconds.
Answer:
P = 7500 [W]
Explanation:
First We must use Newton's second law to find the force. Newton's Second Law tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
m = mass = 150 [kg]
a = acceleration = 5 [m/s²]
![F = 150*5\\F = 750 [N]](https://tex.z-dn.net/?f=F%20%3D%20150%2A5%5C%5CF%20%3D%20750%20%5BN%5D)
We know that the work is determined by multiplying the force by the distance, in this way the units of the work are [N*m] which corresponds to 1 Joule [J].
And the power is determined by dividing the work by the time, in this way we have that [J/s] corresponds to 1 [W].
We must convert the speed from kilometers per hour to meters per second.
![36[km/hr]*1000[\frac{m}{1km}]*[\frac{1hr}{3600s} ]=10 [m/s]](https://tex.z-dn.net/?f=36%5Bkm%2Fhr%5D%2A1000%5B%5Cfrac%7Bm%7D%7B1km%7D%5D%2A%5B%5Cfrac%7B1hr%7D%7B3600s%7D%20%5D%3D10%20%5Bm%2Fs%5D)
where:
P = power [W]
F = force = 750 [N]
v = 10 [m/s]
![P = 750*10\\P = 7500 [W]](https://tex.z-dn.net/?f=P%20%3D%20750%2A10%5C%5CP%20%3D%207500%20%5BW%5D)
Answer:
7.3 newtons to the west
Explanation:
3.7kg × 11a - 3.7kg × ? = 3.7n
Answer:
F = 3 fo
Explanation:
The electric force is given by Coulomb's law
F = k q₁ q₂ / r²
where k is the Coulomb constant and is equal to 8.99 109
with the initial charge the force is
Fo = k q₁ q₂ / r²
Fo =k q₁ q₂ / r²
In this case it is indicated that charge 1 is changed by the lithium atom a = 3 P
we substitute
F = k 3p p / r²
F = 3 (k p² / r²)
F = 3 fo
we see that the charge increases by three orders of magnitude
Answer
given,
mass of people = 65 kg
number of people =
diameter of the merry-go-round = 4.2 m
radius = 2.1 m
angular velocity = 0.8 rad/s
moment of inertia = 1760 kg m²
Using the law of conservation of angular momentum, we have
L₁= L₂
I₁ω₁ =I₂ω₂
I₁ω₁= ( I₁+ 4 m r²)ω²
( 1760 x 0.8) = ( 1760 + 4 x 65 x 2.12)ω²
1408 = 2311.2 ω²
ω² = 0.609
ω = 0.781 rad/s
b) If the people jump of the merry-go-round radially, they exert no torque.
hence, it will not change the angular momentum of the merry-go-round. It will continue to move with the same ω .
