Okay, here is my stab at this, I hope it helps!
You know the bullet's initial velocity, V₀ = 450 m/s
You know the final velocity, V = 220 m/s
You also know how long the bullet accelerates (actually decelerates), 14cm, or .14 m
With this information, you learn that you need this equation.
V² = V₀² + 2a (x - x₀), because we have all the information except a, which is the acceleration. So putting it into the equation, it looks like this.
(220m/s)² = (450m/s)² +2a(.14m - 0m)
I'll let you solve the rest, but here are some hints. Your answer will be really big because the bullet slows down really quickly in a really small distance, and you answer will be negative, because this acceleration is causing the bullet to go slower, which is also called deceleration. Hope that helps!
Answer:
Finally current will be
i = 0.35 A
Explanation:
As we know that power of the bulb is given by the formula

now we have

R = 240 ohm
so we have


now the current in the bulb is given as


now when length of the filament is double
so the resistance of the wire also gets double
so we have



now the current in the bulb is given as



Answer:
t = 25 seconds
Explanation:
Given that,
Distance, d = 115 m
Initial speed, u = 4.2 m/s
Final speed, v = 5 m/s
We need to find the time taken in increasing the speed.
We know that,
Acceleration,
....(1)
The third equation of kinematics is as follows :

Hence, it will take 25 seconds to increase the speed.
Answer:
20 rad/s
Explanation:
mass, m = 12 kg
radius, r = 0.250 m
Moment of inertia of cylinder, I = 1/2 mr²
I = 0.5 x 12 x 0.250 x 0.250 = 0.375 kgm^2
Work done = Change in kinetic energy
Initial K = 0
Final K = 1/2 Iω²
W = 1/2 Iω²
ω² = 2W/ I = 2 x 75 / (0.375)
ω = 20 rad/s
Thus, the final angular velocity is 20 rad/s .
Answer:
The answer is "
"
Explanation:
The formula for velocity:

