PHY 1O1 ASSIGNMENT SOLUTIONS 2020
Question No: 1
Is it true or wrong that if anyone say that, can something that is “speeding up” it means it is also have a negative acceleration? Either true or wrong justify your answer with solid reason.
Ans:
If object moving in negative direction that has a negative velocity and is speeding up. In this condition when an object is speeding up and the acceleration is in the same direction as a velocity. The object has a negative acceleration.
Examples:
Time Velocity
0 0
1 -2
2 -4
3 -6
4 -8
So, it is true when an object is speeding up and it also has a negative acceleration.
Question No: 2
a) Is it possible for an object that, object with zero acceleration have velocity? If yes give an example if not give its proof.
Ans:
Yes it is possible for an object that has zero acceleration but have a velocity.
Example:
When an object move in uniform motion, moving in straight line and have a constant speed. In this case object has non zero velocity and the velocity not change so the acceleration is zero.
b) Is it possible for an object that, object with zero velocity have acceleration? If yes give an example if not give its proof.
Ans:
Yes, an object has zero velocity but have acceleration.
Example:
When you throw a ball upward in the air. When you throw it up then it has positive velocity and negative acceleration. As it hits highest point then it has zero velocity and has acceleration.
Question No: 3
In Newton’s famous event that why, apple always falls to the Earth. Suppose the weight of the apple is 2.5 N. Then calculate the force that does the apple exert on the Earth and also mention the direction of the calculated force?
Solution:
By Newton Third Law of Motion
By Newton's Third Law, the force of the Earth on the apple is exactly equal and opposite to the force of the apple on the Earth. By Newton’s Second law, the force of the Earth on the apple is equal to the mass of the apple times g , the accelerations due to gravity. And, the force of the apple on the Earth is equal to the mass of the Earth times the acceleration of the Earth toward the apple. In conclusion, the magnitude of the forces is equal and the direction of the force is upward.
If directed tangent to the circle. The force can indeed accelerate the object by changing its direction but it cannot change its speed.
Question No: 4
An object has a speed/velocity of 25 km/h. suddenly it deviates to the left but maintains the same speed/velocity. Was any force involved in this situation or not? Explain it with a suitable reason. Solution:
Yes, the centripetal force is applied in this situation because the centripetal force acts upon an object moving in a circle at constant speed, the force always acts inward as the velocity of the object by changing its direction but it cannot change its speed.
Example of centripetal force:
Whatever object, if it moves in a circle, there is some force acting upon it to cause it to deviate from its straight-line path, accelerate inwards and move along a circular path.
Question No: 1
Is it true or wrong that if anyone say that, can something that is “speeding up” it means it is also have a negative acceleration? Either true or wrong justify your answer with solid reason.
Ans:
If object moving in negative direction that has a negative velocity and is speeding up. In this condition when an object is speeding up and the acceleration is in the same direction as a velocity. The object has a negative acceleration.
Examples:
Time Velocity
0 0
1 -2
2 -4
3 -6
4 -8
So, it is true when an object is speeding up and it also has a negative acceleration.
Question No: 2
a) Is it possible for an object that, object with zero acceleration have velocity? If yes give an example if not give its proof.
Ans:
Yes it is possible for an object that has zero acceleration but have a velocity.
Example:
When an object move in uniform motion, moving in straight line and have a constant speed. In this case object has non zero velocity and the velocity not change so the acceleration is zero.
b) Is it possible for an object that, object with zero velocity have acceleration? If yes give an example if not give its proof.
Ans:
Yes, an object has zero velocity but have acceleration.
Example:
When you throw a ball upward in the air. When you throw it up then it has positive velocity and negative acceleration. As it hits highest point then it has zero velocity and has acceleration.
Question No: 3
In Newton’s famous event that why, apple always falls to the Earth. Suppose the weight of the apple is 2.5 N. Then calculate the force that does the apple exert on the Earth and also mention the direction of the calculated force?
Solution:
By Newton Third Law of Motion
By Newton's Third Law, the force of the Earth on the apple is exactly equal and opposite to the force of the apple on the Earth. By Newton’s Second law, the force of the Earth on the apple is equal to the mass of the apple times g , the accelerations due to gravity. And, the force of the apple on the Earth is equal to the mass of the Earth times the acceleration of the Earth toward the apple. In conclusion, the magnitude of the forces is equal and the direction of the force is upward.
If directed tangent to the circle. The force can indeed accelerate the object by changing its direction but it cannot change its speed.
Question No: 4
An object has a speed/velocity of 25 km/h. suddenly it deviates to the left but maintains the same speed/velocity. Was any force involved in this situation or not? Explain it with a suitable reason. Solution:
Yes, the centripetal force is applied in this situation because the centripetal force acts upon an object moving in a circle at constant speed, the force always acts inward as the velocity of the object by changing its direction but it cannot change its speed.
Example of centripetal force:
Whatever object, if it moves in a circle, there is some force acting upon it to cause it to deviate from its straight-line path, accelerate inwards and move along a circular path.