A 6 kg object is pulled with a force of 60 N at an angle of 30° across a rough surface, as shown in the diagram below - NSC Technical Sciences - Question 2 - 2021 - Paper 1
Question 2
A 6 kg object is pulled with a force of 60 N at an angle of 30° across a rough surface, as shown in the diagram below.
2.1 State Newton's First Law of Motion in wor... show full transcript
Worked Solution & Example Answer:A 6 kg object is pulled with a force of 60 N at an angle of 30° across a rough surface, as shown in the diagram below - NSC Technical Sciences - Question 2 - 2021 - Paper 1
Step 1
State Newton's First Law of Motion in words.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Newton's First Law of Motion states that an object will remain at rest or move in a straight line at constant velocity unless acted upon by a net external force.
Step 2
Calculate the magnitude of the: Vertical component of the 60 N force
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The vertical component (Fy) of the 60 N force can be calculated using the sine function:
Fy=60imesextsin(30°)=30extN
Step 3
Calculate the magnitude of the: Frictional force experienced by the object if the coefficient of kinetic friction ($\mu_k$) between the surface and the object is 0,13
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
First, we need to find the normal force (FN):
FN=mg−Fy=(6extkg)(9.8extm/s2)−30extN=58.8extN
Now, calculate the frictional force (Ff):
Ff=μkimesFN=0.13imes58.8=7.644extN
Step 4
Calculate the magnitude of the: Horizontal component of the 60 N force
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The horizontal component (Fx) of the 60 N force can be calculated using the cosine function:
Fx=60imesextcos(30°)=51.96extN
Step 5
Calculate the acceleration of the object.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Using Newton's second law, we can calculate the net force:
Fnet=Fx−Ff=51.96extN−7.644extN=44.316extN
Now we apply F=ma to find the acceleration:
a=mFnet=644.316=7.386extm/s2
Step 6
How will an increase in the angle between the applied force and the horizontal influence the friction?
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Decrease. As the angle increases, the vertical component of the force will increase and thus the normal force will decrease, resulting in a reduction of the frictional force.
Step 7
State Newton's Third Law in words.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
When object A exerts a force on object B, object B simultaneously exerts an equal and opposite force on object A.
Step 8
Draw a labelled free-body diagram of ALL the forces acting on the caravan.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The free-body diagram should include arrows indicating all forces:
Normal force (FN) acting upwards
Gravitational force (Fg) acting downwards
Tension force (FT) from the car pulling the caravan
Frictional force (Ff) acting in the opposite direction of motion.