Assume the wooden piece prevents the balloon from rising, is not so heavy as to cause the balloon to descend. and the 15 m/s is horizontal velocity “riding the wind,” That horizontal velocity does not affect the time the wood will take to reach the ground after release. Initial vertical velocity is zero.
s = u t + 1/2 g t^2
s is the height above ground, 300 m.
u is initial vertical velocity, zero.
t is time to reach the ground.
g is acceleration of gravity near Earth, 9.8 m/s^2.
300 m = 0 t + 1/2 (9.8 m/s^2) t^2
300 m = (4.9 m/s^2) t^2
61.22 s^2 = t^2
7.82 seconds = t
(D) The gravitational force between the astronaut and the asteroid.
Reason :
All the other forces given in the options, except (D), doesn't account for the motion of the astronaut. They are the forces that act between nucleons or atoms and neither of them accounts for an objects motion.
Answer:
I = 113.014 kg.m^2
m = 2075.56 kg
wf = 3.942 rad/s
Explanation:
Given:
- The constant Force applied F = 300 N
- The radius of the wheel r = 0.33 m
- The angular acceleration α = 0.876 rad / s^2
Find:
(a) What is the moment of inertia of the wheel (in kg · m2)?
(b) What is the mass (in kg) of the wheel?
(c) The wheel starts from rest and the tangential force remains constant over a time period of t= 4.50 s. What is the angular speed (in rad/s) of the wheel at the end of this time period?
Solution:
- We will apply Newton's second law for the rotational motion of the disc given by:
F*r = I*α
Where, I: The moment of inertia of the cylindrical wheel.
I = F*r / α
I = 300*0.33 / 0.876
I = 113.014 kg.m^2
- Assuming the cylindrical wheel as cylindrical disc with moment inertia given as:
I = 0.5*m*r^2
m = 2*I / r^2
Where, m is the mass of the wheel in kg.
m = 2*113.014 / 0.33^2
m = 2075.56 kg
- The initial angular velocity wi = 0, after time t sec the final angular speed wf can be determined by rotational kinematics equation 1:
wf = wi + α*t
wf = 0 + 0.876*(4.5)
wf = 3.942 rad/s
Answer:
To obtain the power, we first need to find the work made by the force.
1) To calculate the work, we need the next equation:
So the force is given by the problem so our mission is to find 'dx' in terms of 't'
2) we know that:
So we have:
Then:
3) Finally, we replace everything:
After some calculation, we have as a result that the work is:
161.9638 J.
4) To calculate the power we need the next equation:
So
P = 161.9638/4.7 = 34.46 W
A device that uses electricity and magnetism to create motion is called a "Motor" (which converts electric energy into mechanical energy) & <span>In a reverse process, a device that uses motion and magnetism can be used to create "Electromagnetism".
In short, 1st Blank = Motor
2nd Blank = Electromagnetism
Hope this helps!</span>
