Physics Required Practical 7

Question 1

Investigating the effect of changing the force on the acceleration of an object whilst keeping the mass constant.

Answer 1

• attach toy car to a piece of string
• string is looped around a pulley
• other end of the spring is attached to a 100g mass
• weight of mass provides the force acting on the toy car
• draw chalk lines on the desk at regular intervals
• hold toy car at starting point
• let go of the car
• because there is a resultant force acting through the string, the car will accelerate though the bench
• record the time that the car passes each distance marker
• repeat the experiment several times but in each case decrease the mass on the string
• so weight/force is decreasing each time
• acceleration of the toy car is proportional to the mass on the other end of the string

Question 2

What if the toy car is moving rapidly?

Answer 2

• difficult to record an accurate time
• record on mobile phone
• play video back

Question 3

Investigating how varying the mass of the object affects the acceleration produced by a constant force

Answer 3

• keep force constant by keeping the mass at the end of the string the same
• attach a mass to the toy car e.g. 200g
• record car as it accelerates along the bench
• repeat the experiment whilst increasing the mass attached to the car
• as we increase the mass of the toy car, acceleration decreases.