Forces: Weight On Planet Question?

Question

Hi. Does anyone know how to solve this?
On a planet you find that a 16.4 kg object falls downward 6.0 m in 3.2 seconds. What is the magnitude of acceleration due to gravity? How much does the object weigh on this planet? How much would this object weigh back on earth?
Thanks!

Answer 1

1.s=1/2gt^2
g=2s/t^2=2*6/(3.2)^2
1.17m/sec^2

2.weight=mg=16.4*1.17=19.22 N

3.0n earth=16.4*9.8=160.72 N

Answer 2

To find the magnitude of acceleration, you just use the distance and time, ignoring mass for now. You have a y of 6 m and a t of 3.2 s, so you can solve for g, gravitational acceleration, in the formula y = 0.5*gt^2. To find the object's weight on this planet, W', just multiply the object's mass by the alien gravity. To find the object's weight on Earth, W, take the mass and multiply by good old terrestial gravity, 9.8 m/s^2.

Answer 3

Since D=1/2*G*T^2: 6=1/2*G*3.2^2. Solving this shows that G equals approximately 1.17M/sec^2. On this planet this object would weigh 1.17*16.4=19.21 Newtons. On Earth this same object would weigh 9.8*16.4=160.72 Newtons.

Answer 4

First you need to find the gravitational acceleration on the planet. You can do that with the equation

(Change in x) = (initial velocity)(time) + (1/2)(acceleration)(time)^2

In this case, the acceleration is gravitational (on earth it's 9.8 m/s^2)

Change in x is 6 meters.
Time is 3.2 seconds.
Initial velocity is 0.
Find magnitude of acceleration.

Once that's done, use F=ma (or Weight = mass*gravitational acceleration, they're the same concept) to find the weight on earth. Mass is 16.4 kg. Acceleration on earth is 9.8 m/s^2.