Answer:
v = -1.8t+36
20 seconds
360 m
40 seconds
36 m/s
The object speed will increase when it is coming down from its highest height.
Explanation:

Differentiating with respect to time we get

a) Velocity of the object after t seconds is v = -1.8t+36
At the highest point v will be 0

b) The object will reach the highest point after 20 seconds

c) Highest point the object will reach is 360 m


d) Time taken to strike the ground would be 20+20 = 40 seconds
![[tex]v=u+at\\\Rightarrow v=0+0.9\times 2\times 20\\\Rightarrow v=36\ m/s](https://tex.z-dn.net/?f=%5Btex%5Dv%3Du%2Bat%5C%5C%5CRightarrow%20v%3D0%2B0.9%5Ctimes%202%5Ctimes%2020%5C%5C%5CRightarrow%20v%3D36%5C%20m%2Fs)
Acceleration will be taken as positive because the object is going down. Hence, the sign changes. 2 is multiplied because the expression is given in the form of 
e) The velocity with which the object strikes the ground will be 36 m/s
f) The speed will increase when the object has gone up and for 20 seconds and falls down for 20 seconds. The object speed will increase when it is coming down from its highest height.
Answer:
0.96 m
Explanation:
First, convert km/h to m/s.
162.3 km/h × (1000 m/km) × (1 hr / 3600 s) = 45.08 m/s
Now find the time it takes to move 20 m horizontally.
Δx = v₀ t + ½ at²
20 m = (45.08 m/s) t + ½ (0 m/s²) t²
t = 0.4436 s
Finally, find how far the ball falls in that time.
Δy = v₀ t + ½ at²
Δy = (0 m/s) (0.4436 s) + ½ (-9.8 m/s²) (0.4436 s)²
Δy = -0.96 m
The ball will have fallen 0.96 meters.
Answer:
The answer to your question is Pe = 2452.5 J
Explanation:
Data
mass = 50 kg
height = 5 m
gravity = 9.81 m/s²
Process
The energy of this process is Potential energy which is proportional to the mass of the body, the gravity and the height of the body.
Pe = mgh
Substitution
Pe = (50)(5)(9.81)
Simplification
Pe = 2452.5 J
The kinetic energy decreases
Answer:
4.3 * 10^28 kg
Explanation:
Given:
Period, T = 84s
Radius of satellite orbit, r = 8*10^6
Using the relation :
M = 4π²r³ / GT²
Where G = Gravitational constant, 6.67 * 10^-11
M = 4*π^2*(8*10^6)^3 / 6.67 * 10^-11 * 84^2
M = (20218.191872 * 10^18) / 47063.52 * 10^-11
M = 0.4295937 * 10^18 - (-11)
M = 0.4295937 * 10^29
M = 4.295937 * 10^28 kg
M = 4.3 * 10^28 kg
Mass of planet Nutron = 4.3 * 10^28 kg