Answer:
Yes we can find the initial velocity of car without finding acceleration.
u = 10 m/s.
Explanation:
Given that
s=20 m
Car takes 4 s to come in rest.
We know that when acceleration is constant then we can apply motion equation
----------1
------2
From equation 1 and 2

So we can say that

Given that the velocity of car at final condition will be zero (v=0)


From the above equation we can find the initial velocity of car without finding the acceleration

u = 10 m/s
Answer:
Radius of the solenoid is 0.93 meters.
Explanation:
It is given that,
The magnetic field strength within the solenoid is given by the equation,
, t is time in seconds

The induced electric field outside the solenoid is 1.1 V/m at a distance of 2.0 m from the axis of the solenoid, x = 2 m
The electric field due to changing magnetic field is given by :

x is the distance from the axis of the solenoid
, r is the radius of the solenoid


r = 0.93 meters
So, the radius of the solenoid is 0.93 meters. Hence, this is the required solution.
At the rear.
PWC stands for personal watercraft, and it is a small powerboat. The main components of a PWC are the hull (body of the boat), deck (surface where people walk/stand), throttle (controls speed), steering nozzle and water intake.
Acceleration, a = (v - u)/t
where v is the final velocity, u is the initial velocity, and t is the time.
This formula on a velocity time graph represents the slope of the graph.