Answer:
A. 39.2 m/s
B. 78.4 m
Explanation:
Data obtained from the question include:
Time (t) = 4 s
Acceleration due to gravity (g) = 9.8 m/s²
A. Determination of the brick's velocity.
Time (t) = 4 s
Acceleration due to gravity (g) = 9.8 m/s²
Velocity (v) =?
v = gt
v = 4 × 9.8
v = 39.2 m/s
Thus, the brick's velocity after 4 s is 39.2 m/s
B. Determination of how far the brick fall in 4 s.
Time (t) = 4 s
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
h = ½gt²
h = ½ × 9.8 × 4²
h = 4.9 × 16
h = 78.4 m
Thus, the brick fall 78.4 m during the time.
Answer:
Electric field, 
Explanation:
It is given that,
Magnitude of charge, 
Force experienced, 
We need to find the electric field at the origin. It is given by :
So, the electric field at the origin is 
. Hence, this is the required solution.
Answer:
option (b)
Explanation:
According to the Pascal's law
F / A = f / a
Where, F is the force on ram, A be the area of ram, f be the force on plunger and a be the area of plunger.
Diameter of ram, D = 20 cm, R = 20 / 2 = 10 cm
A = π R^2 = π x 100 cm^2
F = 3 tons = 3000 kgf
diameter of plunger, d = 3 cm, r = 1.5 cm
a = π x 2.25 cm^2
Use Pascal's law
3000 / π x 100 = f / π x 2.25
f = 67.5 Kgf
Answer:
The cannonball fly horizontally before it strikes the ground, S = 323.25 m
Explanation:
Given data,
The height of the cliff, h = 80 m
The horizontal velocity of the cannonball, Vₓ = 80 m/s
The range of the cannon ball with initial vertical velocity is zero is given by the formula,
S = 323.25 m
Hence, the cannonball fly horizontally before it strikes the ground, S = 323.25 m
Answer:
4.988kW
Explanation:
According to the question, energy E extracted from the ocean breaker is directly proportional to the intensity I. It can be expressed mathematically as E ∝ I
E = kI where k is the constant of proportionality.
From the formula; k = E/I
This shows that increase in energy extracted will lead to increase in its intensity and vice versa.
If the device produces 10.0 kW of power on a day when the breakers are 1.20 m high
E = 10kW and I = 1.20m
k = 10/1.20
k = 8.33kW/m
To know how much energy E that will be produced when they are 0.600 m high, we will use the same formula
k = E/I where;
k = 8.33kW/m
I = 0.600m
E = kI
E = 8.33 × 0.6
E = 4.998kW
The device will produce energy of 4.998kW when they are 0.600m high.
