Let's list the given information. The frictional force, denoted as Ff, is equal to 0.200 N. We have to find the normal force, denoted as Fn. The relationship between Ff and Fn is written as:
Ff = μFn
where μ is the coefficient of friction
If there is no given data for μ, we can't solve this problem. Suppose μ = 0.5, then the normal force would be:
Fn = Ff/μ = 0.2/0.5 = 0.4 N
Answer:
The right solution is "61.557 MJ". A further explanation is given below.
Explanation:
The given values are:
Force,
F = 306 N
Drive,
D = 125 miles,
i.e.,
= 201168
meters
As we know,
The work done will be:
= 
On substituting the given values, we get
= 
= 
On converting it in "MJ", we get
= 
= 
We are given the gravitational potential energy and the height of the ball and is asked in the problem to determine the mass of the ball. the formula to be followed is PE = mgh where g is the gravitational acceleration equal to 9.81 m/s^2. substituting, 58.8 J = m*9.8 m/s^2 * 30 m; m = 0.2 kg.