Explanation:
first you have to find accelerarion, it is given that the initial velocity(u) is 3 m/s, distance travelled(s) be 2m finall it came to rest so final velocity be 0m/s
now using the 3rd law of motion
v^2=u^2+2as
0=9+2a2
a= -9/4m/s^2
now force=mass×accelration
=2kg×(-9/4)m/s^2
=4.5 N
4.5 newton force applied on the book!
✌️:)
To break this problem down, let's start with what we know. The equation given finds one component of the velocity and multiplies it by the change in time. This will not find the acceleration that the first two answers say it will, meaning that the answer isn't A or B.
That leaves us with the final two answers, C and D. If the projectile was launched horizontally and we were trying to find the horizontal displacement, we wouldn't need to use cosθ to find the horizontal velocity, meaning that our answer is most likely C) <span>the horizontal displacement of a projectile launched at an angle!</span><span />
<h3><u>Answer;</u></h3>
B. 16.2 m/s
<h3><u>Explanation</u>;</h3>
Using the equation;
v = u + at; where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken;
u = 21 m/s, a= -2.4 m/s^2 and t = 2 seconds
Therefore;
v = 21 + ((-2.4) × 2)
= 21 - 4.8
<u> = 16.2 m/s</u>
Answer:
Radii of Super giant > giant > main sequence star.
Explanation:
A star becomes a giant after all the hydrogen available for fusion, in a main sequence star is depleted and its outer shell of the star expands.
Super giant and giant stars are very large in size compared to a main sequence star. For example, if a giant star has 20 times the diameter of main sequence star, the super giant's diameter is almost 300 times or even more than a main sequence star.
Most of the stars are main sequence stars. After a star has spent a few million or even a few billion years as a main sequence star, it becomes a giant and a super giant star. These are the later stages of development of development of the main sequence star. Giant and super giant phase of a star's life is very short compared to the main sequence star.
Answer:
near a flame and a hot plate
Explanation:
