Explanation:
It is given that,
The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation as:

Where,
x is in meters and t is in sec
We know that,
Velocity,

(a) i. t = 2 s

At t = 4 s

(b) Acceleration,

Pu t = 3 s in the above equation
So,

Hence, this is the required solution.
Answer:
a)T total = 2*Voy/(g*sin( α ))
b)α = 0º , T total≅∞ (the particle, goes away horizontally indefinitely)
α = 90º, T total=2*Voy/g
Explanation:
Voy=Vo*sinα
- Time to reach the maximal height :
Kinematics equation: Vfy=Voy-at
a=g*sinα ; g is gravity
if Vfy=0 ⇒ t=T ; time to reach the maximal height
so:
0=Voy-g*sin( α )*T
T=Voy/(g*sin( α ))
- Time required to return to the starting point:
After the object reaches its maximum height, the object descends to the starting point, the time it descends is the same as the time it rises.
So T total= 2T = 2*Voy/(g*sin( α ))
The particle goes totally horizontal, goes away indefinitely
T total= 2*Voy/(g*sin( α )) ≅∞
T total=2*Voy/g
Almost all telescopes have a circular mirror. The area of a circle is proportional to

where

is the radius of the circle, the constant of proportionality being


Therefore the area of 150 meter telescope would be

times bigger than the area of the smaller (10 meter) telescope.
No. The moon always keeps the same side facing us. Its rotation and revolution periods are equal.
If the earth's mass were half its actual value but its radius stayed the same, the escape velocity of the earth would be
.
<h3>What is an escape velocity?</h3>
The ratio of the object's travel distance over a specific period of time is known as its velocity. As a vector quantity, the velocity requires both the magnitude and the direction. the slowest possible speed at which a body can break out of the gravitational pull of a certain planet or another object.
The formula to calculate the escape velocity of earth is given below:-

Given that earth's mass was half its actual value but its radius stayed the same. The escape velocity will be calculated as below:-

.
Therefore, If the earth's mass were half its actual value but its radius stayed the same, the escape velocity of the earth would be
.
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