k = spring constant of the spring = 100 N/m
m = mass hanging from the spring = 0.71 kg
T = Time period of the spring's motion = ?
Time period of the oscillations of the mass hanging is given as
T = (2π) √(m/k)
inserting the values in the above equation
T = (2 x 3.14) √(0.71 kg/100 N/m)
T = (6.28) √(0.0071 sec²)
T = (6.28) (0.084) sec
T = 0.53 sec
hence the correct choice is D) 0.53
Answer:
The net force is 1.8N
Explanation:
Given that the formula for force is Force = mass×acceleration. So you have to substitute the values into the formula :

Let mass = 0.15kg,
Let acceleration = 12m/s²,


Answer:
Acceleration of the object is
.
Explanation:
It is given that, the position of the object is given by :
![r=[2\ m+(5\ m/s)t]i+[3\ m-(2\ m/s^2)t^2]j](https://tex.z-dn.net/?f=r%3D%5B2%5C%20m%2B%285%5C%20m%2Fs%29t%5Di%2B%5B3%5C%20m-%282%5C%20m%2Fs%5E2%29t%5E2%5Dj)
Velocity of the object, 
Acceleration of the object is given by :

![a=\dfrac{d^2}{dt^2}([2\ m+(5\ m/s)t]i+[3\ m-(2\ m/s^2)t^2]j)](https://tex.z-dn.net/?f=a%3D%5Cdfrac%7Bd%5E2%7D%7Bdt%5E2%7D%28%5B2%5C%20m%2B%285%5C%20m%2Fs%29t%5Di%2B%5B3%5C%20m-%282%5C%20m%2Fs%5E2%29t%5E2%5Dj%29)
Using the property of differentiation, we get :

So, the magnitude of the acceleration of the object at time t = 2.00 s is
. Hence, this is the required solution.
The gravitational potential energy referred to the ground level is given by

where m is the mass of the object,

is the gravitational acceleration and h is the height of the object with respect to the ground.
Therefore in our problem the potential energy is