Word Problem
Which would require a greater force –– accelerating a 5 kg mass at 8 m/s2 or a 6 kg mass at 7 m/s2?
Solution
We already know that Newton’s second law of motion states that the force applied on an object
is the product of the object’s mass and its acceleration.
For the first case, let the mass = m1 and acceleration = a1. For the second case, let the mass = m2 and acceleration = a2.
Let’s calculate the force for both the cases.
First case | Second case | |
Mass | m1 = 5 kg | m2 = 6 kg |
Acceleration | a1 = 8 m/s2 | a2 = 7 m/s2 |
Force | F1 = m1 X a1
= 5 kg X 8 m/s2 = 40 N |
F2 = m2 X a2
= 6 kg X 7 m/s2 = 42 N |
Since the magnitude of force in the second case is greater than the first case, accelerating a 6 kg mass at 7 m/s2 will require greater force than accelerating a 5 kg mass at 8 m/s2.