Two significant figures, the 6 and the 9
A falling skydiver opens his parachute. A short time later, the weight of the skydiver-parachute system and the drag force exerted on the system are equal in magnitude. The following statements predicts the motion of the skydiver at this time
<u>The skydiver is moving downward with constant speed.</u>
Explanation:
Immediately on leaving the aircraft, the skydiver accelerates downwards due to the force of gravity. There is no air resistance acting in the upwards direction, and there is a resultant force acting downwards. The skydiver accelerates towards the ground.
The forces acting on a falling leaf are : gravity and air resistance.
The net force and the acceleration on the falling skydiver is upward.
An upward net force on a downward falling object would cause that object to slow down. The skydiver thus slows down.
As the speed decreases, the amount of air resistance also decreases until once more the skydiver reaches a terminal velocity.
<u>A skydiver falling at a constant speed opens his parachute. When the skydiver is falling, the forces are unbalanced.</u>
Answer
given,
mass of the person, m = 50 Kg
length of scaffold = 6 m
mass of scaffold, M= 70 Kg
distance of person standing from one end = 1.5 m
Tension in the vertical rope = ?
now equating all the vertical forces acting in the system.
T₁ + T₂ = m g + M g
T₁ + T₂ = 50 x 9.8 + 70 x 9.8
T₁ + T₂ = 1176...........(1)
system is equilibrium so, the moment along the system will also be zero.
taking moment about rope with tension T₂.
now,
T₁ x 6 - mg x (6-1.5) - M g x 3 = 0
'3 m' is used because the weight of the scaffold pass through center of gravity.
6 T₁ = 50 x 9.8 x 4.5 + 70 x 9.8 x 3
6 T₁ = 4263
T₁ = 710.5 N
from equation (1)
T₂ = 1176 - 710.5
T₂ = 465.5 N
hence, T₁ = 710.5 N and T₂ = 465.5 N
Answer:

Explanation:
The energy needed to ionize a hydrogen atom in the ground state is:

The energy of the photon is related to the wavelength by

where
h is the Planck constant
c is the speed of light
is the wavelength
Solving the formula for the wavelength, we find

Complete question:
The classic Goodyear blimp is essentially a helium balloon— a big one, containing 5700 m³ of helium. If the envelope and gondola have a total mass of 4300 kg, what is the maximum cargo load when the blimp flies at a sea-level location? Assume an air temperature of 20°C.
Answer:
52.4 kN
Explanation:
The helium at 20°C has a density of 0.183 kg/m³, and the cargo load is the weight of the system, which consists of the envelope, the gondola, and the helium.
The helium mass is the volume multiplied by the density, thus:
mHe = 5700 * 0.183 = 1043.1 kg
The total mass is then 5343.1 kg. The weight is the mass multiplied by the gravity acceleration (9.8 m/s²), so:
W = 5343.1*9.8
W = 53362.38 N
W = 52.4 kN