Answer:
Solution:
we have given the equation of motion is x(t)=8sint [where t in seconds and x in centimeter]
Position, velocity and acceleration are all based on the equation of motion.
The equation represents the position. The first derivative gives the velocity and the 2nd derivative gives the acceleration.
x(t)=8sint
x'(t)=8cost
x"(t)=-8sint
now at time t=2pi/3,
position, x(t)=8sin(2pi/3)=4*squart(3)cm.
velocity, x'(t)=8cos(2pi/3)==4cm/s
acceleration, x"(t)==8sin(2pi/3)=-4cm/s^2
so at present the direction is in y-axis.
Answer:
Explanation:
The gravitational force exerted on the satellites is given by the Newton's Law of Universal Gravitation:
Where M is the mass of the earth, m is the mass of a satellite, R the radius of its orbit and G is the gravitational constant.
Also, we know that the centripetal force of an object describing a circular motion is given by:
Where m is the mass of the object, v is its speed and R is its distance to the center of the circle.
Then, since the gravitational force is the centripetal force in this case, we can equalize the two expressions and solve for v:
Finally, we plug in the values for G (6.67*10^-11Nm^2/kg^2), M (5.97*10^24kg) and R for each satellite. Take in account that R is the radius of the orbit, not the distance to the planet's surface. So 
and 
(Since 
). Then, we get:
In words, the orbital speed for satellite A is 7667m/s (a) and for satellite B is 7487m/s (b).
Velocity = Frequency x Wavelength
= 18 x 13 = 234 mm/s
<h3>Answer;</h3>
<u>It would make the lens stronger. </u>
<h3>Explanation;</h3>
- The focal length is the distance between the optical center or the center of the lens to the focal point of a convex or concave lens.
- The power of the convex lens is lens ability to undertake refraction or bend light. It is given as the reciprocal of focal length.
- Power of the lens = 1/ f; therefore the smaller the focal length the higher the power and the larger the focal length the lower the power.
- Thus; decreasing the focal length of a convex lens makes the lens stronger.
Answer: option C.
Fabrics such as cotton and silk are synthetic polymers
Explanation:
Fabrics such as cotton and silk are synthetic polymers because cotton and silk are natural polymers meaning they are gotten from natural source. Cotton is gotten from cotton plants and it is composed of cellulose which is a carbohydrates.
Silk also is gotten from animals I.efrom insect fibre or the cocoons of the larvae of the mulberry silkworm which is a polymer.
