Answer:
D. 4 m
Explanation:
According to the work-energy theorem, the work done by the force acting on a body modifies its kinetic energy.
The car comes to rest after a given distance, so . Recall the definition of work , here F is the constant force acting on the car, d is its traveled distance and is the angle between the force and the displacement, since friction force acts opposite to the direction of motion :
We have:
Thus:
Answer:
no additional information required.
Explanation:
given,
vertical height, h = 35 m
acceleration due to gravity, g = 9.8 m/s²
time taken by the bullet to fall in the water = ?
initial vertical velocity of the bullet = 0 m/s
using equation of motion for the time calculation
t = 2.67 s
The time taken by the bullet to fall in the ocean is equal to 2.67 s.
Hence, there is no additional information required.
Answer:
Explanation:
You have that a parallel plate capacitor has a total energy of E when the distance between the plates is d and the charge on each plate is Q.
You take into account the following formula for the stored energy in the capacitor:
(1)
The capacitance C of the parallel plate capacitor is given by the following formula is:
(2)
A: area of the plates
ε0: dielectric permittivity of vacuum
You replace the expression (2) into the equation (1):
(3)
the previous formula is the expression for the total energy stored for the given parameters A, d and Q.
If the distance between the plates is twice and it is required that the energy is three times the initial energy, to find the value of the charge you use the equation (3):
(4)
d' = 2d
E' = 3E
Q': required charge
You replace the values of d' and E' in the equation (4) and then divide the result with the equation (3):
Finally, you solve for Q':
Then, the required charge is √6Q , to obtain three times the initial energy E, when the distance between plates is doubled.