Answer:
B) 1.2 N, toward the center of the circle
Explanation:
The circumference of the circle is:
C = 2πr
C = 2π (0.70 m)
C = 4.40 m
So the velocity of the ball is:
v = C/t
v = 4.40 m / 0.60 s
v = 7.33 m/s
Sum of the forces in the radial direction:
∑F = ma
T = m v² / r
T = (0.015 kg) (7.33 m/s)² / (0.70 m)
T = 1.2 N
The tension force is 1.2 N towards the center of the circle.
Answer:
96%
Explanation
Let A the total area of the galaxy, is modeled as a disc:
A = πR^2 = π (25 kpc)^2
And let a be the area that astronomers are able to see:
a = πr^2 = π(5 kpc)^2
The percentage that can be seen is equal to 100 times the ratio of the areas, of the galaxy and the "visible" part:
P = 100 a/A = (5/25)^2 = 100/25 = 4%
Therefore, the percentage of the galaxy not included, i.e. not seen is:
(100-4)% = 96%
Answer:
Explanation:
A pressure that causes the Hg column to rise 1 millimeter is called a torr. The term 1 mmHg used can replaced by the torr.
1 atm = 760 torr = 14.7 psi.
A.
120 mmHg
Psi:
760 mmHg = 14.7 psi
120 mmHg = 14.7/760 * 120
= 2.32 psi
Pa:
1mmHg = 133.322 Pa
120 mmHg = 120 * 133.322
= 15998.4 Pa
B.
80 mmHg
Psi:
760 mmHg = 14.7 psi
80 mmHg = 14.7/760 * 80
= 1.55 psi
Pa:
1mmHg = 133.322 Pa
80 mmHg = 80 * 133.322
= 10665.6 Pa
37° Celsius is equal to 98.6° Fahrenheit
Its B: reduce the amount of energy needed to do the work by putting the work onto something else
