Answer:

Explanation:
Let assume that pole vaulter begins running at a height of zero. The pole vaulter is modelled after the Principle of Energy Conservation:


The expression is simplified and final height is cleared within the equation:


![h_{B} = \frac{[(11\,\frac{m}{s} )^{2}-(1.3\,\frac{m}{s} )^{2}]}{2\cdot (9.807\,\frac{m}{s^{2}} )}](https://tex.z-dn.net/?f=h_%7BB%7D%20%3D%20%5Cfrac%7B%5B%2811%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29%5E%7B2%7D-%281.3%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29%5E%7B2%7D%5D%7D%7B2%5Ccdot%20%289.807%5C%2C%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D%20%29%7D)

Question: Find acceleration of a refrigerator 30s after a person begins pushing it at a force of 400 N, If the mass of the refrigerator is 10 kg.
Answer:
40 m/s²
Explanation:
Applying,
F = ma................Equation 1
Where F = Force applied to the refrigerator, m = mass of the refrigerator, a = acceleration of the refrigerator.
make a the subject of the equation
a = F/m............ Equation 2
From the question,
Given: F = 400 N, m = 10 kg
Substitute these values into equation 2
a = 400/10
a = 40 m/s²
I think it is D because gas particles move the fastest but if not then it is A