To solve this problem we will apply the concepts related to energy conservation. Here we will use the conservation between the potential gravitational energy and the kinetic energy to determine the velocity of this escape. The gravitational potential energy can be expressed as,

The kinetic energy can be written as,

Where,
Gravitational Universal Constant
Mass of Earth
Height
Radius of Earth
From the conservation of energy:

Rearranging to find the velocity,
Escape velocity at a certain height from the earth
If the height of the satellite from the earth is h, then the total distance would be the radius of the earth and the eight,


Replacing the values we have that


Therefore the escape velocity is 3.6km/s
Answer:

Explanation:
When the screw is turned by two turns then change in the length of the wire is given as




now we know by the formula of Young's modulus

so we have



Answer:
The ratio of the momentum imparted to gun #1 to that imparted to gun #2 is equal to 2 : 1
Explanation:
Detailed explanation and calculation is shown in the image below
Answer:
t=0.704s
Explanation:
A child is running his 46.1 g toy car down a ramp. The ramp is 1.73 m long and forms a 40.5° angle with the flat ground. How long will it take the car to reach the bottom of the ramp if there is no friction?
from newton equation of motion , we look for the y component of the speed and look for the x component of the speed. we can then find the resultant of the speed

Vy^2=0+2*9.8*1.73sin40.5
Vy^2=22.021
Vy=4.69m/s
Vx^2=u^2+2*9.81*cos40.5
Vy^2=25.81
Vy=5.08m/s
V=(Vy^2+Vx^2)^0.5
V=47.71^0.5
V=6.9m/s
from newtons equation of motion we know that force applied is directly proportional to the rate of change in momentum on a body.
f=force applied
v=velocity final
u=initial velocity
m=mass of the toy, 0.046
f=ma
f=m(v-u)/t
v=u+at
6.9=0+9.8t
t=6.9/9.81
t=0.704s