Newton’s Second Law Lab
Write Newton’s 2nd Law (the equation) in terms of N, kg, m/s2:
Notice that if you increase mass or acceleration in the equation you increase the force.
Explain why:
In this lab you will roll balls of equal volume (size) but of different mass to see what happens to force as mass varies.
Based on the equation of Newton’s 2nd Law, write your hypothesis of what will happen to force as mass varies (is different):
Set up the track by propping one end up 10 cm. Put the cup at the end of the track so a ball will roll into the cup. You will roll a ping pong ball and a golf ball down this track. Do these balls vary by mass or volume?
Find the mass in kg of each ball on the grams scale. Write their mass below (remember divide grams by 1000 to convert to kg!):
Golf ball ______ping pong ball ______
Now roll the 2 balls down the track into the cup. Place the ball at the start of the ramp each time. Roll each ball 10 times. Measure how far the cup moves with your ruler. Measure the distance in cm. Write down your measurements and average them in the table below. What are you measuring (N, kg, or m/s2) by measuring the distance that the cup moves?
Distance cup moves golf ball (cm) / Distance cup moves ping pong ball (cm)Average distance golf ball = / Average distance ping pong ball =
Was your hypothesis correct about what happens to force as mass increases? Explain!
Now figure out the force on the cup for each ball.
2. Write the equation for force again (Newton’s 2nd Law!):
3. What are the SI units of force?
4. What are the SI units of mass?
5. What is the rate of acceleration in m/s2when objects accelerate towards Earth?
6. Now figure out the force in Newtons of each ball hitting the cup below by finding the weight in N for each ball. Be sure to include all units in your calculations and show your work!
Force of golf ball:
N golf ball = ______
Force of ping pong ball:
N ping pong ball = ______
7. Explain why increasing mass increases force.
8. Explain why inertia is directly related to an object mass (is it easier to move the cup with the golf ball or the ping pong ball?).