Answer:
3 j
Explanation:
12.0 kilo / 4.00 meters = 3 j
Answer:
64 m
Explanation:
Using the following symbols
x: distance
v: velocity
a: constant acceleration
t: time
v₀: initial velocity
x₀: initial position
The equations of motion for a constant acceleration are given by:
(1) x = 0.5at²+v₀t+x₀
(2) v = at+v₀
From equation (2) you can calculate the time t it takes the car to come to a complete stop.
(3) t = (v-v₀)/a
Now you plug equation (3) in equation(1):
(4) x = 0.5a((v-v₀)/a)²+v₀((v-v₀)/a)+x₀
In equation (4) the position x is the only unknown.
Two objects in physical contact with each other are in thermal equilibrium when they reach the same temperature and an exchange of heat energy no longer occurs.<span> According to HyperPhysics, the relation of thermal equilibrium follows the Zeroth Law of Thermodynamics, which states that “if two systems are at the same time in thermal equilibrium with a third system, they are in thermal equilibrium with each other.” </span>
Answer:
a=(v-u)/t is how you find acceleration.
Answer:
115 m/s, 414 km/hr
Explanation:
There are two forces acting on a skydiver: gravity and air resistance (drag). At terminal velocity, the two forces are equal and opposite.
∑F = ma
D − mg = 0
D = mg
Drag force is defined as:
D = ½ ρ v² C A
where ρ is the fluid density,
v is the velocity,
C is the drag coefficient,
and A is the cross sectional surface area.
Substituting and solving for v:
½ ρ v² C A = mg
v² = 2mg / (ρCA)
v = √(2mg / (ρCA))
We're given values for m and A, and we know the value of g. We need to look up ρ and C.
Density of air depends on pressure and temperature (which vary with elevation), but we can estimate ρ ≈ 1.21 kg/m³.
For a skydiver falling headfirst, C ≈ 0.7.
Substituting all values:
v = √(2 × 80.0 kg × 9.8 m/s² / (1.21 kg/m³ × 0.7 × 0.140 m²))
v = 115 m/s
v = 115 m/s × (1 km / 1000 m) × (3600 s / hr)
v = 414 km/hr
