To find the average force exerted onBill’s head we need to use the formula for f
ID: 1664001 • Letter: T
Question
To find the average force exerted onBill’s head we need to use the formula for force. Thisformula is based on Newton’s second law which states, theacceleration produced by a net force on an object is directlyproportional to the magnitude of the net force, is in the samedirection as the net force, and is inversely proportional to themass of the object. This means that acceleration is equal to netforce over mass, or Force is equal to mass times acceleration.Also, because we are given the weight of the head we use theequation for weight, which is weight equals mass times theacceleration of gravity (w = mg). We find the mass of the headfirst using the equation for weight (m=w/g) (m=20 lb/9.8 m/sec/sec= 2.04 lb) We then find the acceleration of the head using (Vf = Vi+ at) (a = 8.94 m/sec/0.01 sec = 894 m/sec^2).Then we can find theforce by plugging in the found values into the equation for force(F =ma) (F = 2.04 lb. x 894 m/sec^2 = 1824.5 N) Force ofBill’s on windshield = 1824.5 N
Explanation / Answer
You wrong in the final equation. It is true that F=ma but your unit is wrong. If F is in N, a is in m/sec^2 then m must be in kg. So the right answer is 89/9.81*894=8110 (N)