The force involved in the orbiting of the earth is gravity!
I think the answer is Helium.
Please tell me if I'm wrong.
Answer:
Explanation:
a )
moment of inertia of hollow ball
= 2 / 3 mR² , m is mass and R is radius of the ball
= 2 / 3 x 120 x .5²
= 20 kg m²
b )
5 rpm = 5 / 60 rps
n = .0833
angular velocity ω = 2πn= 2 x 3.14 x .0833= .523 rad /s
angular acceleration = increase in angular velocity / time
= .523 - 0 / 20
α = .02615 rad /s²
c )
Torque = moment of inertia x angular acceleration
= 20 x .02615
= .523 Nm
d )
θ = 1/2 α t²
= .5 x .02615 x 20²
= 5.23
2π n = 5.23 where n is required number
n = .83
Answer:
A) 10 m/s
Explanation:
We know that according to conservation of momentum,
m1v1 + m2v2 = m1u1 + m2u2 ..............(equation 1)
where m1 and m2 are masses of two bodies, v1 and v2 are initial velocity before collision and u1 and u2 are final velocities after collision respectively.
From the given data
If truck and car are two bodies
truck : m1 = 2000 Kg v1 = 5 m/s u1 = 0
car : m2 = 1000 kg v2 = 0 u2 = ?
final velocity of truck and initial velocity of car are static because the objects were at rest in the respective time.
substituting the values in equation 1, we get
(2000 x 5) + 0 = 0 + (1000 x u2)
u2 =
x 5
= 10 m/s
Hence after collision, car moves at a velocity of 10 m/s