As we know that centripetal force =mv^2/r
given data is
m = mass
v = speed
r = radius
putting values we get
= 85 x 15^2 / 20
= 956.25 N
option d is correct
Left. Opposite of the direction the box is pushed.
You can find your answer here www.rsc.org/education/teachers/resources/jesei/minerals/students.htm
Given :
The mass of the balloon was 1890 kg and had a volume of 11,430 m3 .
The balloon floats at a constant height of 6.25m above the ground.
To Find :
The density of the hot air in the balloon.
Solution :
We know,
Volume × ( Density of surrounding air - Density of hot air ) = mass
Putting given values in above equation, we get :

Therefore, the density of hot air in the balloon is 1.125 kg m³.