Question

plessessssssss solve questions number (4),(5);

Answer 1

4.
Retardation = -μg

S = (v² - u²) / (2a)
= (v² - u²) / (2 × -μg)
= (0² - 20²) / (2 × 0.4 × 10)
= 50 m
_________________________

5.
Retardation = -μg

S = (v² - u²) / (2a)
= (v² - u²) / (2 × -μg)

Rearrange the above equation to find μ

μ = (v² - u²) / (2 × -Sg)
= (0² - 7²) / (2 × -10 × 9.8)
= 1/4

Friction = μN
= μmg
= 1/4 × mg

∴ Friction = 1/4 × Weight of the car