Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force
When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
Answer:
The beach ball's velocity at the moment it was tossed into the air is <u>4.9 m/s.</u>
Explanation:
Given:
Time taken by the ball to reach maximum height is,
We know that, velocity of an object at the highest point is always zero. So, final velocity of the ball is,
Also, acceleration acting on the ball is always due to gravity. So, acceleration of the ball is,
The negative sign is used as acceleration is a vector and it acts in the downward direction.
Now, we have the equation of motion relating initial velocity, final velocity, acceleration and time given as:
Where, 'u' is the initial velocity.
Plug in the given values and solve for 'u'. This gives,
Therefore, the beach ball's velocity at the moment it was tossed into the air is 4.9 m/s
Answer:
T= 4.24sec
Explanation:
We are going to use the formula below to calculate.
Where T is period
L is length of rod
g is acceleration due to gravity =
From the problem, the rod is pivoted at 1/4L which means that three quarter of the rod was used for the oscillation. lets call this
= 4.4625m
thus
T= 4.24sec