Answer: 1m/s
Explanation: according to the law of conservation of linear momentum in an isolated system, the momentum of the gun equals that of the bullet.
Mathematically
Mb×Vb = Mg×Vg
Where Mb = mass of bullet = 1/100 = 0.01 kg
Vb = velocity of bullet = 200 m/s
Mg = mass of gun = 2kg
Vg = recoil velocity of gun =?
0.01×200 = 2×Vg
Vg = 0.01×200/2
Vg = 0.01×100
Vg = 1m/s
It can be fire ice water grass and stuff like that
In 1920, after returning from Army service, he produced a successful model and in 1923 turned it over to the Northeast Electric Company of Rochester for development.
Answer:
7.875 ft/s
Explanation:
L = 15 ft
dx/dt = 3 ft/s
x = 9 ft
Let the top of ladder is coming down with the rate of dy/dt.
use Pythagorean theorem
L^2 = x^2 + y^2 .... (1)
Differentiate both sides with respect to t
0 = 2 x dx/dt + 2y dy/dt
x dx/dt = - y dy/dt
When, x = 9 ft then y = ? . Put this in equation (1)
15^2 = 9^2 + y^2
225 - 81 = y^2
y = 12 ft
So
dy/dt = - x (dx/dt) / y = - 9 (3) / 12 = - 9/4 ft/s
Let A be the area of the triangle
A = 1/2 (base)(height)
A = 1/2 (x y)
Differentiate both sides with respect to t
dA/dt = 0.5 (y dx/dt + x dy/dt)
dA/dt = 0.5 [ 12 (3) - 9 (9/4)]
dA/dt = 0.5(36 - 81 /4) = 31.5 / 4 = 7.875 ft/s