Answer:
The angular speed is 0.83 rad/s.
Explanation:
Given that,
Mass of disk M=49 kg
Radius = 1.7 m
Mass of child m= 29 kg
Speed = 2.6 m/s
Suppose if the disk was initially at rest , now how fast is it rotating
We need to calculate the angular speed
Using conservation of momentum


Put the value into the formula



Hence, The angular speed is 0.83 rad/s.
Answer:
A) t = 4.40 s
, B) v = 23.86 m / s
, c) v_y = - 43.12 m / s
, D) v = 49.28 m/s
Explanation:
This is a projectile throwing exercise,
A) To know the time of the stone in the air, let's find the time it takes to reach the floor
y = y₀ +
t - ½ g t²
as the stone is thrown horizontally v_{oy} = 0
y = y₀ - ½ g t²
0 = y₀ - ½ g t²
t = √ (2 y₀ / g)
t = √ (2 95 / 9.8)
t = 4.40 s
B) what is the horizontal velocity of the body
v = x / t
v = 105 / 4.40
v = 23.86 m / s
C) The vertical speed when it touches the ground
v_y =
- g t
v_y = 0 - 9.8 4.40
v_y = - 43.12 m / s
the negative sign indicates that the speed is down
D) total velocity just hitting the ground
v = vₓ i ^ + v_y j ^
v = 23.86 i ^ - 43.12 j ^
Let's use Pythagoras' theorem to find the modulus
v = √ (vₓ² + v_y²)
v = √ (23.86² + 43.12²)
v = 49.28 m / s
we use trigonometry for the angle
tan θ = v_y / vₓ
θ = tan⁻¹ (-43.12 / 23.86)
θ = -61
Firstly, we must find the equation the speed, it can be obtained by the derivative of x =<span>x = 4.0t2 - 32t + 36, it means v= 8.0t-32. the particule stops means v= 0, and 0= 8.0t-32, which implies 8t=32, so t=4s, and then x(t=4) = 4.0(4)^2 - 32(4) + 36= - 28m
so x = - 28 m</span>