Answer:
20 J
Explanation:
Given:
Weight of the book is, 
Height or displacement of the book is, 
The work done on the book to raise it to a height of 2 m on a shelf is against gravity. The gravitational force acting on the book is equal to its weight. Now, in order to raise it, an equal amount of force must be applied in the opposite direction.
So, the force applied by me should be equal to weight of the body and in the upward direction. The displacement is also in the upward direction.
Now, work done by the applied force is equal to the product of force applied and displacement of book in the direction of the applied force.
Therefore, work done is given as:
Therefore, the work done to raise a book to a height 2 m from the floor is 20 J.
Answer:
<h3>The answer is 0.47 kg</h3>
Explanation:
The mass of the object given it's momentum and velocity can be found by using the formula
where
p is the momentum
v is the velocity
We have
We have the final answer as
<h3>0.47 kg</h3>
Hope this helps you
Explanation:
Given that,
Initial speed of a car, u = 60 km/h = 16.67 m/s
Acceleration, a = 2m/s²
Final speed, v = 120 km/h = 33.33 m/s
We need to find the distance traveled and the time taken to make the distance.
acceleration = rate of change of velocity
let the distance be d.
Hence, the distance traveled and the time taken to make the distance is 208.25 m and 8.33 seconds respectively.
Answer:
The second dart leaves the gun two times as faster than the first one.
Explanation:
Assuming no energy loss during the spring-dart energy transfer, we have by the conservation of energy principle
Given an arbitrary 
and its double, 
, launch velocities are
