Actually, the speed of the earth is the same everywhere, taking the angular speed as the valid measure of the speed
Friction occurs when the surfaces and heat of two surfaces grind against each other.
I think these are the answers
Yes that is correct or in other form, True
A 'displacement' always consists of a magnitude and a direction. The two cars you just described have displacements with the same magnitude ... 5 km. But if they didn't both drive in the same direction, then their displacements are different.
Remember:
-- 10 m/s² up and 10 m/s² down are different accelerations
-- 30 mph East and 30 mph West are the same speed but different velocity.
-- 5 km North and 5 km South are the same distance but different displacement.
Answer:
a = 17.68 m/s²
Explanation:
given,
length of the string, L = 0.8 m
angle made with vertical, θ = 61°
time to complete 1 rev, t = 1.25 s
radial acceleration = ?
first we have to calculate the radius of the circle
R = L sin θ
R = 0.8 x sin 61°
R = 0.7 m
now, calculating at the angular velocity


ω = 5.026 rad/s
now, radial acceleration
a = r ω²
a = 0.7 x 5.026²
a = 17.68 m/s²
hence, the radial acceleration of the ball is equal to 17.68 rad/s²