Answer:
Relative density is a ratio of the density of a certain material to the density of a reference material. Relative density has no unit, because the units of the material in question cancel out with the units of the reference material. For example, say a cooking oil’s density is 0.9 g/cm^3.
Explanation:
Answer:
b) Springs oscillate with the same frequency,
Explanation:
expression for frequency of vibration of mass hanging from a spring is given as follows
f = 
k is force constant of spring and m is mass vibrating .
In the present case, if mass stretches the spring by x and remains balanced
mg = k x

g and x are same for both cases
will also be same for both cases .
Hence frequency of vibration will also be same for both the balls .
Answer:
the coefficient of Kinetic friction between the tires and road is 0.38
Option A) .38 is the correct answer
Explanation:
Given that;
final velocity v = 0
initial velocity u = 15m/s
time taken t = 4 s
acceleration a = ?
from the equation of motion
v = u + at
we substitute
0 = 15 + a × 4
acceleration a = -15/4 = - 3.75 m/s²
the negative sign tells us that its a deacceleration so the sign can be ignored.
Deacceleration due to friction a = μ × g
we substitute
3.75 = μ × 9.8
μ = 3.75 / 9.8 = 0.3826 ≈ 0.38
Therefore the coefficient of Kinetic friction between the tires and road is 0.38
Option A) .38 is the correct answer