a substance's density is the same at a certain pressure and temperature, and the density of one substance is usually different than another substance.
Answer:
<em>The force required is 3,104 N</em>
Explanation:
<u>Force</u>
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = ma
Where a is the acceleration of the object.
On the other hand, the equations of the Kinematics describe the motion of the object by the equation:

Where:
vf is the final speed
vo is the initial speed
a is the acceleration
t is the time
Solving for a:

We are given the initial speed as vo=20.4 m/s, the final speed as vf=0 (at rest), and the time taken to stop the car as t=7.4 s. The acceleration is:


The acceleration is negative because the car is braking (losing speed). Now compute the force exerted on the car of mass m=1,126 kg:

F= 3,104 N
The force required is 3,104 N
Answer:
Explanation:
If M be mass of moon and m be mass of spacecraft
potential energy of moon -spacecraft system
= - G M m / R where R is radius of orbit of spacecraft
kinetic energy of spacecraft in the orbit
= 1/2 m v² = GMm / 2R
Total energy of spacecraft
= GMm / 2R - G M m / R
= - GMm / 2R
for spacecraft to leave the orbit, energy required
= GMm / 2R
= 6.67259 x 10⁻¹¹ x 7.36 x 10²² x 14800 / (2 x 1.79877 x 10⁶)
= 202035.8 x 10⁵ J .
This is the formula you need to memorize:
D = 1/2 · a · T²
Distance = (1/2) · (acceleration) · (Time²)
This formula tells the distance an object falls in any amount of time.
This question tells you the distance (58m), and you know the acceleration (gravity, 9.8 m/s²), so you can use this formula to find the time.
Distance = (1/2) · (acceleration) · (Time²)
58m = (1/2) · (9.8 m/s²) · (Time²)
Divide each side by (4.9 m/s²) : Time² = (58/4.9) seconds²
Take the square root of each side: <em>Time = 3.44 seconds </em>