Answer:
10.93m/s with the assumption that the water in the lake is still (the water has a speed of zero)
Explanation:
The velocity of the fish relative to the water when it hits the water surface is equal to the resultant velocity between the fish and the water when it hits it.
The fish drops on the water surface vertically with a vertical velocity v. Nothing was said about the velocity of the water, hence we can safely assume that the velocity if the water in the lake is zero, meaning that it is still. Therefore the relative velocity becomes equal to the velocity v with which the fish strikes the water surface.
We use the first equation of motion for a free-falling body to obtain v as follows;
v = u + gt....................(1)
where g is acceleration due to gravity taken as 9.8m/s/s
It should also be noted that the horizontal and vertical components of the motion are independent of each other, hence we take u = 0 as the fish falls vertically.
To obtain t, we use the second equation of motion as stated;
Given; h = 6.10m.
since u = 0 for the vertical motion; equation (2) can be written as follows;
substituting;
Putting this value of t in equation (1) we obtain the following;
v = 0 + 9.8*1.12
v = 10.93m/s
Answer:
A. friction is greatly reduced.
Explanation:
Maglev train runs on the principle of repulsion force due to magnetic field
here we know that magnetic field will apply force on the train which helps to levitate train in air
This is why it runs forward due to other component of magnetic force and hence it can run with high speed in air with least friction as there is no two surfaces in contact with each other
So here we can say that
Train run with very high speed due to least value of friction between two surfaces which moves relative to each other
so correct answer is
A. friction is greatly reduced.
<span>density of lead = 11.34 g/cm^3 </span>
<span>mass = density x volume = 11.34 g/cm^3 x 45.3 = 513.7 g is the mass of a cube of lead</span>
Answer:
9.6 m/s
Explanation:
Equation is v=d/t so plug 120m to d (distance) and 12.5 sec to t (time).
v=120/12.5
v=9.6 meters per second
Answer:
4.05×10⁶ N.
Explanation:
The following data were obtained from the question:
Breadth (B) = 4 m
Length (L) = 10 m
Standard pressure (P) = 101325 Nm¯²
Force (F) =..?
Next, we shall determine the area of the wall. This can be obtained as follow:
Area (A) = length (L) × breadth (B)
A = 10 × 4
A = 40 m²
Finally, we shall determine the force exerted on one side of the wall as follow:
Standard pressure (P) = 101325 Nm¯²
Area (A) = 40 m²
Force (F) =.?
Pressure (P) = Force (F) /Area (A)
101325 = F/40
Cross multiply
F = 101325 × 40
F = 4.05×10⁶ N.
Therefore, a force of 4.05×10⁶ N was exerted on one side of the wall.
