Answer:

Explanation:
given,
coefficient of kinetic friction, μ = 0.25
Speed of sled at point A = 8.6 m/s
Speed of sled at point B = 5.4 m/s
time taken to travel from point A to B.
we know,
J = F Δ t
J is the impulse
where F is the frictional force.
t is the time.
we also know that impulse is equal to change in momentum.

frictional force
F = μ N
where as N is the normal force
now,






time taken to move from A to B is equal to 1.31 s
Answer: <em>4</em><em>2</em><em>.</em><em>3</em><em>2</em><em> </em><em>ms-1</em>
Explanation:
v = u+ at
v = 24.4 + ( 3.2×5.6)
v = 42.32 ms-1
Answer:
16.25 m
Explanation:
we know that the equation pf parabola

from bellow figure the coordinate of parabola is (600,65) that is y=600 and x=65
putting the the value of y and x in the equation of parabola

k=0.0001805
now the equation is

we have to find the value of y at x=300m
so 
y=16.25 m
Answer:
5
Explanation:
electrons can be more than det
Hello,
<span>A police car parked on the side of the highway emits a 1200 Hz sound that bounces off a vehicle farther down the highway and returns with a frequency of 1250 Hz.
How fast is the vehicle going?
Doppler equation formula: </span>ƒL = ƒS(v - vL)/(v - vS)
The wave returns with a frequency of 1250 Hz, the <span>echo frequency is higher; the car must be traveling towards the police car.
</span><span>The wave echo is coming back towards the police car at the same speed as the sound wave travels towards the moving car so t</span><span>he relative speed between the cars is half of the speed of the echo.
* </span><span>speed of sound equals about 337 m/s </span>
2v / 337 = (1250/1200) - 1
<span>2v = 14.04 m/s </span>
<span>v = 7.02 m/s
</span>
Thus, the vehicle is going 7.02 m/s.
Faith xoxo