Answer:
1.) U = 39.2 m/s
2.) t = 4s
Explanation: Given that the
height H = 78.4m
The projectile is fired vertically upwards under the acceleration due to gravity g = 9.8 m/s^2
Let's assume that the maximum height = 78.4m. And at maximum height, final velocity V = 0
Velocity of projections can be achieved by using the formula
V^2 = U^2 - 2gH
g will be negative as the object is moving against the gravity
0 = U^2 - 2 × 9.8 × 78.4
U^2 = 1536.64
U = sqrt( 1536.64 )
U = 39.2 m/s
The time it takes to reach its highest point can be calculated by using the formula;
V = U - gt
Where V = 0
Substitute U and t into the formula
0 = 39.2 - 9.8 × t
9.8t = 39.2
t = 39.2/9.8
t = 4 seconds.
Make Neptune closer to the sun because then it would have a stronger gravitation pull. Because the closer the objects are, they will have a stronger gravitaional force and when the object has more mass, the gravity is also stronger. So, if the mass is reduced, the gravity force would be reduced, but if you bring neptune closer, the gravity force would increase
Exercise is the answer hope i helped you
Answer:
The minimum inductance needed is 2.78 H
Explanation:
Given;
frequency of the AC, f = 26.5 Hz
the root mean square voltage in the circuit, 
= 41.2 V
the maximum current in the circuit, I₀ = 126 mA
The root mean square current is given by;
The inductive reactance is given by;
The minimum inductance needed is given by;
Therefore, the minimum inductance needed is 2.78 H
