Answer:
F= 5.71 N
Explanation:
width of door= 0.91 m
door closer torque on door= 5.2 Nm
In order to hold the door in open position we need to exert an equal and opposite torque, to the door closer torque, on the door.
so wee need to exert 5.2 Nm torque on the door.
If we want to apply minimum force to exert the required torque we need to apply force perpendicularly on the door knob (end of door) so that to to greater moment arm.
T= r x F
T= r F sin∅
F= T/ (r * sin∅)
F= 5.2/ (0.91 * 1)
F= 5.71 N
Answer: This is not easy lol
Explanation:
Answer: f=150cm in water and f=60cm in air.
Explanation: Focal length is a measurement of how strong light is converged or diverged by a system. To find the variable, it can be used the formula:
= (nglass - ni)( - ).
nglass is the index of refraction of the glass;
ni is the index of refraction of the medium you want, water in this case;
R1 is the curvature through which light enters the lens;
R2 is the curvature of the surface which it exits the lens;
Substituting and calculating for water (nwater = 1.3):
= (1.5 - 1.3)( - )
= 0.2()
f = = 150
For air (nair = 1):
= (1.5 - 1)( - )
f = = 60
In water, the focal length of the lens is f = 150cm.
In air, f = 60cm.
Plants,such as trees poduce oxygen to help animals like insects or humans can bresth snd surviave.
The temperature of a balloon is
lowered with liquid nitrogen. The balloon appears to deflate because the gas in
the balloon lost energy and condensed. The answer is letter D.