Question

why does a satellite in a circular orbit travel at a constant speed (choose all that apply)

a. there is no force acting along the direction of motion of the satellite
b. the only force is the force of gravity
c. there is no component of net force in the radial direction
d. the net force acting on the satellite is toward the center of the path
e. There is a component of the net force acting in the direction of the motion of the satellite
f. the gravitational force acting on the satellite is balanced by the centrifugal force

(I know its not F bc centrifugal force its really a real thing but the rest... idk)

a box of mass 10 kg is pressed but not attached to an ideal spring compressing the spring a distance of 2.5cm after it is released the box slides up a frictionless incline and eventually stops at a vertical height h, the same experiment is repeated with the same box and spring but with an initial compression of 5cm the vertical height the box reaches the second time is ______

i'm thinking its 2x because its 2x the compression but let me know I might be very very wrong

Answer 1

a. there is no force acting along the direction of motion of the satellite - true
b. the only force is the force of gravity - true
d. the net force acting on the satellite is toward the center of the path - true
f. the gravitational force acting on the satellite is balanced by the centrifugal force

The gravitational force on the satellite is always perpndicular to its direction of motion. This force only changes the direction and always pushes it towards the center of the path. There is no force in the direction of motion and no acceleration hence uniform velocity. centifugal force is a pseduo force applied in a non-inertial frame of the satellite. It appear to be pushed away from the center, from the frame of rotation. It is equal to centripetal force in magnitude.

Box mass m= 10 kg

spring compressed by 2.5 cm

spring const. - k

spring energy = 1/2k(0.025)²

mass raised to a height h

pot. energy = mgh

no friction

conserving the total mechanical energy

mgh = 1/2k(0.025)²

when spring is compressed by 5 cm

spring energy = 1/2k(0.05)²

conserving the total energy

mgh' = 1/2k(0.05)² = 4 mgh

h' new height = 4h