A motobike's tire rotates with a constant angular speed of 62.8 rad/s. The radius of a tire is 30cm. Assuming that no slipping occurs, the linear speed at a point 20 cm from the tire's center is:
Chọn một:
a.
10 m/s
b.
20 m/s
C.
18.8 m/s
d.
12.6 m/s

12.6 m/s

Explanation:

We know that the linear speed v = rω where r = radius and ω = angular acceleration. Given that ω = 62.8 rad/s and r = 20 cm from center = 0.2 cm

So, v = rω

= 0.2 m × 62.8 rad/s

= 12.56 m/s

≅12.6 m/s

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg