Answer:
v = R w
With this expression we see that for each point at different radius the tangential velocity is different
Explanation:
They indicate that the angular velocity is constant, that is
w = dθ / dt
Where θ is the radius swept angle and t the time taken.
The tangential velocity is linear or
v = dx / dt
Where x is the distance traveled in time (t)
In the definition of radians
θ = s / R
Where s is the arc traveled and R the radius vector from the pivot point, if the angle is small the arc (s) and the length (x) are almost equal
θ = x / R
We substitute in the speed equation
v = d (θ R) / dt
The radius is a constant for each point
v = R dθ / dt
v = R w
With this expression we see that for each point at different radius the tangential velocity is different
Answer:
A. The time it takes the projectile to reach the top of its path is about 1 second.
Explanation:
Hi there!
The equation of the velocity of a projectile fired straight up is the following:
v = v0 + g · t
Where:
v = velocity of the projectile.
v0 = initial velocity.
g = acceleration due to gravity (≅ -9.8 m/s² considering the upward direction as positive)
t = time.
When the projectile reaches the top of its path, its velocity is zero, then, using the equation of velocity, we can solve it for the time:
v = v0 + g · t
0 = 10 m/s - 9.8 m/s² · t
t = -10 m/s / -9.8 m/s²
t = 1.0 s
The time it takes the projectile to reach the top of its path is about 1 second.
The answer I had got was C x
Note:
1 A (armstrong) = 10⁻¹⁰ m
1 nm (nanometer) = 10⁻⁹ m
Given:
Radius of a krypton atom = 1.9 A = 1.9 x 10⁻¹⁰ m
Part (a)

Answer: 0.019 nm
Part (b)
The diameter of a krypton atom = 2*1.9A = 3.8 A = 3.8 x 10⁻¹⁰ m.
The number of krypton atoms within a length of 1.0 mm is

Answer: About 2.632 x 10⁶ atoms
Part (c)
The radius of a krypton atom is
1.9 A = (1.9 x 10⁻¹⁰ m)*(10² cm/m) = 1.9 x 10⁻⁸ cm
The volume of a krypton atm is

Answer: 2.873 x 10⁻²³ cm³