Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum

and making
the subject then
and since
is initial velocity of car, value given as 4 m/s,
is the initial velocity of the three cars stuck together, value given as 2 m/s and
is the final velocity which is unknown. By substitution

(b)
Initial kinetic energy is given by

Final kinetic energy is given by

The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
Answer:
The greatest speed of the car is 19.36m/s
Explanation:
The maximum speed the car will attain without skidding is given by:
F= uN = umg ...eq1
But F = mv^2/r
mv^2/r = umg
Dividing both sides by m, leaves you with:
V= Sqrt(ugr)
Where u = coefficient of static friction
g = acceleration due to gravity
r = raduis
Given:
U = 0.82
r=0.82
g= 9.8m/s
V = Sqrt(0.82 × 9.8 × 45)
V = Sqrt(374.85)
V = 19.36m/s
Explanation:
Given that,
Current, I = 0.015 A
Voltage, V = 240 volts
We need to find the resistance. Using Ohm's law we can find it as follows :

So, When a current of 0.015 A passes through human body at 240 volts p.d it causes 16000 ohms of resistance.
true if you are refering to the desing of the experimnt as it does identify the variable