A concave lens is a lens that has at least one of its surfaces or both surfaces curved inwards. Due to this reason, this lens diverges the light that falls on it and hence is also called a diverging lens. The concave lens is thinner in the middle compared to its edges. These are used in flashlights, binoculars, telescopes, etc.
Please see attached image for reference.
It has three significant figure
I assume the block plows into the bank of sand with a velocity of 6 m/s and comes to a stop in 2 s.
Answer:
0.04225 Nm
Explanation:
N = Force applied = 5 N
= Coefficient of static friction = 0.65
d = Diameter of knob = 1.3 cm
r = Radius of knob = ![\frac{d}{2}=\frac{1.3}{2}=0.65\ cm](https://tex.z-dn.net/?f=%5Cfrac%7Bd%7D%7B2%7D%3D%5Cfrac%7B1.3%7D%7B2%7D%3D0.65%5C%20cm)
Force is given by
![F=N\mu\\\Rightarrow F=5\times 0.65\\\Rightarrow F=3.25\ N](https://tex.z-dn.net/?f=F%3DN%5Cmu%5C%5C%5CRightarrow%20F%3D5%5Ctimes%200.65%5C%5C%5CRightarrow%20F%3D3.25%5C%20N)
When we multiply force and radius we get torque
Torque on thumb
![\tau_t=F\times r\\\Rightarrow \tau_t=3.25\times 0.0065\\\Rightarrow \tau_t=0.021125\ Nm](https://tex.z-dn.net/?f=%5Ctau_t%3DF%5Ctimes%20r%5C%5C%5CRightarrow%20%5Ctau_t%3D3.25%5Ctimes%200.0065%5C%5C%5CRightarrow%20%5Ctau_t%3D0.021125%5C%20Nm)
Torque on forefinger
![\tau_f=F\times r\\\Rightarrow \tau_f=3.25\times 0.0065\\\Rightarrow \tau_f=0.021125\ Nm](https://tex.z-dn.net/?f=%5Ctau_f%3DF%5Ctimes%20r%5C%5C%5CRightarrow%20%5Ctau_f%3D3.25%5Ctimes%200.0065%5C%5C%5CRightarrow%20%5Ctau_f%3D0.021125%5C%20Nm)
The total torque is given by
![\tau=\tau_t+\tau_f\\\Rightarrow \tau=0.021125+0.021125\\\Rightarrow \tau=0.04225\ Nm](https://tex.z-dn.net/?f=%5Ctau%3D%5Ctau_t%2B%5Ctau_f%5C%5C%5CRightarrow%20%5Ctau%3D0.021125%2B0.021125%5C%5C%5CRightarrow%20%5Ctau%3D0.04225%5C%20Nm)
The most torque that exerted on the knob is 0.04225 Nm
Answer:
have a component along the direction of motion that remains perpendicular to the direction of motion
Explanation:
In this exercise you are asked to enter which sentence is correct, let's start by writing Newton's second law.
circular movement
F = m a
a = v² / r
F = m v²/R
where the force is perpendicular to the velocity, all the force is used to change the direction of the velocity
in linear motion
F = m a
where the force is parallel to the acceleration of the body, the total force is used to change the modulus of the velocity
the correct answer is: have a component along the direction of motion that remains perpendicular to the direction of motion