Answer:
(a) 1.21 m/s² (b) 1.75 m/s²
Explanation:
The initial speed of the car, u = 17.8 m/s
Case 1.
Final speed of the car, v = 23.5 m/s
Time, t = 4.68-s
Acceleration = rate of change of velocity

Case 2.
Final speed of the car, v = 15.3 m/s

Hence, this is the required solution.
Answer:
<h2>602.08 N</h2>
Explanation:
The force supplied by the train can be found by using the formula

w is the workdone
d is the distance
From the question we have

We have the final answer as
<h3>602.08 N</h3>
Hope this helps you
Answer:
Explanation:
θ( p ) + θ( r ) = 90
θ (r) = angle of refraction and θ ( p ) is polarising angle.
given θ ( r ) = 31.8
θ ( p ) = 90 - 31.8 = 58.2 degree
ii ) Tanθ ( p ) = n ( refractive index ) = Tan 58.2 = 1.6
Answer:
S=48.29 m
Explanation:
Given that the height of the hill h = 2.9 m
Coefficient of kinetic friction between his sled and the snow μ = 0.08
Let u be the speed of the skier at the bottom of the hill.
By applying conservation of energy at the top and bottom of the inclined plane we get.
Potential Energy=kinetic Energy
mgh = (1/2) mu²
u² = 2gh
u²=2(9.81)(2.9)
=56.89
u=7.54 m/s
a = - f / m
a = - μ*m*g / m
a = - μg
From equation of motion
v²- u² = 2 -μ g S
v=0 m/s
-(7.54)²=-2(0.06)(9.81)S
S=48.29 m