Answer:3m/s
Explanation:
mass(m)=50kg
Kinetic energy =225 joules
Kinetic energy=(m x (velocity)^2)/2
225=(50 x (velocity)^2)/2
Cross multiplying we get
225x2=50x(velocity)^2
450=50x(velocity)^2
Divide both sides by 50
450/50=(50x(velocity)^2)/50
9=(velocity)^2
Taking the square root of both sides we get
√9=velocity
3=velocity
Velocity=3m/s
Answer:
28.5 m/s
18.22 m/s
Explanation:
h = 20 m, R = 20 m, theta = 53 degree
Let the speed of throwing is u and the speed with which it strikes the ground is v.
Horizontal distance, R = horizontal velocity x time
Let t be the time taken
20 = u Cos 53 x t
u t = 20/0.6 = 33.33 ..... (1)
Now use second equation of motion in vertical direction
h = u Sin 53 t - 1/2 g t^2
20 = 33.33 x 0.8 - 4.9 t^2 (ut = 33.33 from equation 1)
t = 1.17 s
Put in equation (1)
u = 33.33 / 1.17 = 28.5 m/s
Let v be the velocity just before striking the ground
vx = u Cos 53 = 28.5 x 0.6 = 17.15 m/s
vy = uSin 53 - 9.8 x 1.17
vy = 28.5 x 0.8 - 16.66
vy = 6.14 m/s
v^2 = vx^2 + vy^2 = 17.15^2 + 6.14^2
v = 18.22 m/s
Answer:
D = 2.828 m
Explanation:
given,
distance of source of light = 1.24 m below surface of pool
refractive index of the water = n₁ = 1.33
refractive index of air = n₂ = 1
refraction angle be = 90°
let C be the critical angle
Radius = d tan C
d is the depth of the source
Using Snell's law
n₁ sin C = n₂ sin R
1.33 x sin C = 1 x sin 90°
C = 48.75°
hence,
R = 1.24 x tan 48.75°
R = 1.414 m
Diameter = 2 x R
D = 2 x 1.414
D = 2.828 m
Borax, also known as sodium borate, sodium tetraborate,
or disodium tetraborate, is an important boron compound,
a mineral, and a salt of boric acid. Powdered borax is white,
consisting of soft colorless crystals that dissolve easily in water.
Its molecular (chemical) formula is <span>
<span>Na₂B₄O₇·10H₂O or Na₂[B₄O₅(OH)₄]·8H₂O .</span></span>
the new momentum would be 40000 units as momentum = mass × velocity