Answer:
6.37 x 10³ Km
Explanation:
given,
Radius of earth = 6,370,000 m
we know,
1 km = 1000 m
1 m = 0.001 Km
6,370,000 m = 6,370,000 x 0.001
= 6,370 Km
The number 6,370 has 3 significant figure.
To transform this to an exponential number, it is necessary to move the decimal to the left so there is only one digit in front of the decimal point.
Representing the given number in scientific notation
= 6.37 x 10³ Km
Answer:
1.05 J.
Explanation:
Kinetic Energy: This is the energy possessed by a body due to its motion. The S.I unit of kinetic energy is Joules (J). The formula of kinetic energy is given as
Ek = 1/2mv²................. Equation 1
Where Ek = kinetic energy, m = mass of the uniform rod, v = liner velocity of the rod.
But,
v = αr .......................... Equation 2
Where α = angular velocity of the rod, r = radius of the circle.
Given: α = 3.6 red/s, r = 120/2 = 60 cm = 0.6 m.
Substitute into equation 2
v = 3.6(0.6)
v = 2.16 m/s.
Also given: m = 450 g = 0.45 kg.
Substitute into equation 1
Ek = 1/2(0.45)(2.16²)
Ek = 1.05 J.
