10 kilograms of mass weighs 98.1 newtons on Earth,
16.2 newtons on the Moon, 37.1 newtons on Mars,
and other weights in other places.
Answer: 
Explanation:
Given
Length of plank is 1.6 m
Force
is applied on the left side of plank
Force
is applied 43 cm from the left end O.
Mass of the plank is 
for equilibrium
Net torque must be zero. Taking torque about left side of the plank

Net vertical force must be zero on the plank

Simply, apply the formula

and insert the values of m = mass, v = velocity and E = Energy.
The result will be

, m = 1 kg
Answer:
11.4 m/s
Explanation:
The expression for the Centripetal acceleration is :

Where, a is the accleration
v is the velocity around circumference of circle
R is radius of circle
In the given question,
a = g = Acceleration due to gravity as the car is at top = 
v = ?
R = 13.2 m
So,


<u>v = 11.4 m/s</u>
The Wheel & Axle. The wheel has always been considered a major invention in the history of mankind
The Inclined Plane
The Wedge
The Pulley
The Screw