1st derivative gives velocity;
d r(t)/ dt = 2t i + 6 j + 4/t k
2nd derivative gives acceleration;
d^2 r(t)/ dt^2 = 2 i - 4/ t^2
Speed ;
Square root of (4 t^2 + 36 + 16/ t^2)
For a given time, like 2 seconds, t will be 2. And answer of speed will be scalar.
Answer:
0.278 m/s
Explanation:
We can answer the problem by using the law of conservation of momentum. In fact, the total momentum before the collision must be equal to the total momentum after the collision.
So we can write:

where
m = 0.200 kg is the mass of the koala bear
u = 0.750 m/s is the initial velocity of the koala bear
M = 0.350 kg is the mass of the other clay model
v is their final combined velocity
Solving the equation for v, we get

Answer:
A charge of -5.02 nC is uniformly distributed on a thin square sheet of nonconducting material of edge length 21.8 cm. "What is the surface charge density of the sheet"?
Explanation:
Surface charge density is a measure of how much electric charge is accumulated over a surface. It can be calculated as the charge per unit area.
We will convert all parameters in SI units.
Charge = Q = -5.02nC
Q = -5.02×
C
As it is clear from question that Sheet is a square (All sides will be of equal length)
Area = A = (21.8×
m) (21.8×
m) = 4.75×
m²
A = 4.75×
m²
Surface charge density = Q/A
Surface charge density = (-5.02×
C)/(4.75×
m²)
Surface charge density = -1.057×
C
The higher the thermal energy the faster the conduction convection and radiation take place as the particles have more kinetic (movement) energy
First box and third box !