Answer:
Explanation:
Length if the bar is 1m=100cm
The tip of the bar serves as fulcrum
A force of 20N (upward) is applied at the tip of the other end. Then, the force is 100cm from the fulcrum
The crate lid is 2cm from the fulcrum, let the force (downward) acting on the crate be F.
Using moment
Sum of the moments of all forces about any point in the plane must be zero.
Let take moment about the fulcrum
100×20-F×2=0
2000-2F=0
2F=2000
Then, F=1000N
The force acting in the crate lid is 1000N
Option D is correct
Helping verbs come before the main verb, the main verb in the sentence is repair therefor the helping verb would be could.
.
<h3>Explanation</h3>
The Stefan-Boltzmann Law gives the energy radiation <em>per unit area</em> of a black body:
where,
the total power emitted, 
the surface area of the body, 
the Stefan-Boltzmann Constant, and
the temperature of the body in degrees Kelvins.
.
.
.
Keep as many significant figures in as possible. The error will be large when is raised to the power of four. Also, the real value will be much smaller than 
since the emittance of a human body is much smaller than assumed.
Answer:
The work done by gravity during the roll is 490.6 J
Explanation:
The work (W) is:
<em>Where</em>:
F: is the force
d: is the displacement = 20 m
The force is equal to the weight (W) in the x component:
<em>Where:</em>
m: is the mass of the bowling ball = 5 kg
g: is the gravity = 9.81 m/s²
θ: is the degree angle to the horizontal = 30°
Now, we can find the work:
Therefore, the work done by gravity during the roll is 490.6 J.
I hope it helps you!
Answer:
Explanation:
ignore air resistance
Let t be the time of fall for the dropped stone.
½(9.8)t² = 43.12(t - 2.2) + ½(9.8)(t - 2.2)²
4.9t² = 43.12t - 94.864 + 4.9(t² - 4.4t + 4.84)
4.9t² = 43.12t - 94.864 + 4.9t² - 21.56t + 23.716
0 = 21.56t - 71.148
t = 71.148/21.56 = 3.3 s
h = ½(9.8)3.3² = 53.361 = 53 m
or
h = 43.12(3.3 - 2.2) + ½(9.8)(3.3 - 2.2)² = 53.361 = 53 m
