Answer:
786.6 N
Explanation:
mass of car, m = 912 kg
initial velocity of car, u = 31.5 m/s
final velocity of car, v = 24.6 m/ s
time, t = 8 s
Let a be the acceleration of the car
Use first equation of motion
v = u + a t
24.6 = 31.5 + a x 8
a = - 0.8625 m/s^2
Force, F = mass x acceleration
F = 912 x 0.8625
F = 786.6 N
Thus, the force on the car is 786.6 N.
Yup, I think you add all of them
Answer:
22 degree
Explanation:
Angle of incidence, i = 30 degree
the refractive index of water with respect to air is 4/3.
As the ray of light travels from rarer medium to denser medium, that mean air to water, the refraction takes place.
According to Snell's law,
Refractive index of water with respect to air = Sin i / Sin r
Where, r be the angle of refraction
4 / 3 = Sin 30 / Sin r
0.75 = 2 Sin r
Sin r = 0.375
r = 22 degree
Thus, the angle of refraction is 22 degree.
Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
