Question

Question #1 part A

On a planet that is 6.00 times the mass of the Earth and 3.00 times the radius of the Earth, the acceleration of gravity on the surface of that planet would be:                         

A) 4.90 m/s²

B) 6.53 m/s²      

C) 9.80 m/s²                            

D) 13.9 m/s²                        

E) 19.6 m/s²

^{Part B}

A plane performs acrobatic maneuvers in a vertical circle. The pilot passes head down the highest point of the trajectory and just then press the seat with a force of 150 N. The mass of the pilot is 70.0 kg. The radius of the trajectory is 100 m. The speed of the plane at the highest point is: resolve for the speed at highest point

Part C

(In the following situation despise the air). A lightweight elastic spring hangs vertically. A weight of 200 g is attached to the lower end and is brought down slowly, until the spring is stretched 2.0 cm and the weight remains in static equilibrium. If the same weight is hooked on the free end of the spring, but is released to descend by itself, the spring is oscillating, and in each oscillation the spring is stretched:

A) 2.5 cm

B) 3.2 cm   

C) 4.0 cm       

D) 6.0 cm   

E) 8.0 cm

Please resolve all three; Please test is today!!!1

Answer 1

Part A

The acceleration due to gravity is proportional to mass of the planet and inversely proportional to square of radius of planet

Acceleration due to gravity on Earth=9.8 m/s²

Mass of planet under consideration=6 times mass or Earth

Radius of planet under consideration=3 times radius of Earth

Acceleration due to gravity on planet=9.8*6/3²=6.53 m/s²

Correct option is option (b)

Part C

Weight of block=0.2*9.8=1.96 N

Static deflection=0.02m

Stiffness of spring=k=1.96/0.02=98N/m

Let the length by which the spring stretches in the second case be x

From energy conservation, m*g*x=0.5*k*x²

x=m*g/(0.5*k)=0.2*9.8/(0.5*98)=0.04m=4cm

Correct option is (c)