Physical Science with Math

Question

An 75 kg man starts from rest and after 1.45 seconds is running at a speed of 14.0 m/s. The force needed for this man to get up to this speed in 1.45 seconds is ___N.

Answer 1

The formula for force is

 

F = ma

 

where:

F = force

m = mass

a = acceleration

 

We already have the mass.  We just need to find the acceleration using this formula.

 

a = (v_F - v_i) / t

 

where:

v_i = 0 m/s

v_F = 14 m/s

t = 1.45 s

 

Therefore,

 

a = (14 m/s) / (1.45 s)

 

a = 9.66 m/s²

 

Plug in this value of a into the formula for force.

 

F = (75 kg) * (9.66 m/s²)