How do you find instantaneous velocity
Select a point on a distance-time curve graph. Draw a tangent to the curve at that point. Tangent -> hypotenuse of right angled triangle. Opp/adjacent in graph units is vel at that point -> in distance and/or time
Answer:

Explanation:
Given,
Number of turns, N = 645 N
Area, A = 20.25 m²
Earth Magnetic field, B = 5 x 10⁻⁵ T
Maximum Emf = 1.25 V.
Angular velocity, ω = ?
Using Induced Emf formula




Angular velocity of the coil = 
If
and
are perpendicular, then their dot product is zero. This means

Solving for n is trivial; it follows that n = 3.
Answer:
a.The 60 km/HR car
Explanation:
Kinetic Energy: This can be defined as the energy of a body due to motion. The S.I unit of kinetic energy is Joules (J).
It can be expressed mathematically as
Ek = 1/2mv²......................... Equation 1
Where Ek = kinetic energy, m = mass, v = velocity.
(i) A car travelling at 30 km/hr, with a mass of m,
Ek = 1/2(m)(30)²
Ek = 450m J.
(ii) A car travelling at 60 km/hr, with a mass of m/2
Ek = 1/2(m/2)(60)²
Ek = 900m J.
Thus , the car travelling at 60 km/hr at half mass has a greater kinetic energy to the car traveling at 30 km/hr at full mass.
The right option is a.The 60 km/HR car
Answer:2 ft/s
Explanation:
Given
Length of Pole is 9 ft
Length of Joe is 3 ft
Joe walks away from Pole at the rate 4 ft/s
Let Joe is x m away from Pole so its shadow length is x'
From Similar triangle concept

3x'=x+x'
x=2x'
and it is given 
Differentiating


