Answer:
So instantaneous velocity after 9 sec will be 88.2 m/sec
Explanation:
We have given time t = 9 sec
As the object is released from rest so its initial velocity u = 0 m/sec
We have to find its final velocity v
Acceleration due to gravity 
From first equation of motion we know that 

So instantaneous velocity after 9 sec will be 88.2 m/sec
Answer:
r= 2.17 m
Explanation:
Conceptual Analysis:
The electric field at a distance r from a charge line of infinite length and constant charge per unit length is calculated as follows:
E= 2k*(λ/r) Formula (1)
Where:
E: electric field .( N/C)
k: Coulomb electric constant. (N*m²/C²)
λ: linear charge density. (C/m)
r : distance from the charge line to the surface where E calculates (m)
Known data
E= 2.9 N/C
λ = 3.5*10⁻¹⁰ C/m
k= 8.99 *10⁹ N*m²/C²
Problem development
We replace data in the formula (1):
E= 2*k*(λ/r)
2.9= 2*8.99 *10⁹*(3.5*10⁻¹⁰/r)
r =( 2*8.99 *10⁹*3.5*10⁻¹⁰) / (2.9)
r= 2.17 m
Answer:
Final speed of car = 12 m/s
Explanation:
We have equation of motion v = u + at, where v is final velocity, u is initial velocity, a is acceleration and t is time.
a) A cart starts from rest and accelerates at 4.0 m/s² for 5.0 s
v = ?
u = 0 m/s
a = 4.0 m/s²
t = 5 s
v = u + at = 0 + 4 x 5 = 20 m/s
b) Then maintains that velocity for 10 s
v = ?
u = 20 m/s
a = 0 m/s²
t = 10 s
v = u + at = 20 + 0 x 10 = 20 m/s
c) Then decelerates at the rate of 2.0 m/s² for 4.0 s
v = ?
u = 20 m/s
a = -2.0 m/s²
t = 4 s
v = u + at = 20 + -2 x 4 = 12 m/s
Final speed of car = 12 m/s
Answer:
39975kgm/s due east
Explanation:
Given parameters:
Mass of the blimp = 533kg
Velocity = +75m/s due east
Unknown:
Momentum of the body = ?
Solution:
The momentum of a body is the amount of motion it posses.
Momentum is the product of mass and velocity;
Momentum = mass x velocity
Insert the parameters and solve;
Momentum = 533 x 75 = 39975kgm/s
The momentum of the body is 39975kgm/s due east
t=5s
it was correct on my do-now
so I hope it was useful for you