In projectile motion the acceleration at the highest point of curved motion is___.
a. 0 b. g c. undefined d. –g
Which is true about an object was dropped from a 5 storey building?
a. initial velocity is zero b. acceleration is equal to –g
c. displacement is negative d. All of the choices
Which is true about an object was thrown downward from a 5storey building?
a. initial velocity is zero b. acceleration is not equal to –g
c. final velocity is non zero d. All of the choices
In order for an object to accelerate,
a. there must be change in the magnitude of velocity. c. there must be uniform velocity.
b. there must be change in the direction of velocity. d. both options a and b are correct.
The force on this object is
F = - m g
so a = -g
What are your answers?
To determine the correct answers for each question, we can use the principles of projectile motion. Let's go through each question and explain the reasoning behind the correct answer.
1. In projectile motion, the acceleration at the highest point of curved motion is ___.
To answer this question, we need to understand that the acceleration of an object in projectile motion is always directed towards the Earth and has a constant magnitude, represented by 'g' (acceleration due to gravity). At the highest point of curved motion, the object momentarily stops in the vertical direction before changing direction. While it has zero velocity at this point, the acceleration remains constant, directed downward. Therefore, the correct answer is option (d) –g.
2. Which is true about an object dropped from a 5-storey building?
When an object is dropped from a height without any initial velocity, its initial velocity is zero. The acceleration due to gravity acts in the downward direction, which means it is equal to –g. The displacement of the object will be negative because it moves downward. Therefore, the correct answer is option (d) All of the choices.
3. Which is true about an object thrown downward from a 5-storey building?
When an object is thrown downward, its initial velocity is non-zero and directed downward. The acceleration due to gravity still acts in the downward direction and remains equal to –g. The final velocity of the object will depend on the initial velocity and the time it takes to reach the ground. Therefore, the correct answer is option (c) final velocity is non-zero.
4. In order for an object to accelerate,
To understand this question, we need to know that acceleration is defined as any change in an object's velocity. This change can occur either in magnitude or direction, or both. Therefore, both options (a) there must be a change in the magnitude of velocity and (b) there must be a change in the direction of velocity are correct. So, the correct answer is option (d) both options a and b are correct.
By understanding the principles of projectile motion and the concept of acceleration, we can determine the correct answers to these questions.