You are given the mass of the book with an initial
height of 0.77m. You are also given the final height of the book, 2m above the
floor. The problem requires you to find the work done on the book. It is said
that work is equal to force times distance. And that force is equal to mass
times acceleration due to gravity.
W=Fd
W=mgd=mgh
W=(1.7kg)(9.8m/s^2)(2m-0.77m)
W=20.49J
<span>The work is equal to 20.49J.</span>
Answer:
The angular speed of the new system is 
.
Explanation:
Due to the absence of external forces between both disks, the Principle of Angular Momentum Conservation is observed. Since axes of rotation of each disk coincide with each other, the principle can be simplified into its scalar form. The magnitude of the Angular Momentum is equal to the product of the moment of inertial and angular speed. When both disks begin to rotate, moment of inertia is doubled and angular speed halved. That is:
Where:
- Moment of inertia of a disk, measured in kilogram-square meter.
- Initial angular speed, measured in radians per second.
- Final angular speed, measured in radians per second.
This relationship is simplified and final angular speed can be determined in terms of initial angular speed:
Given that 
, the angular speed of the new system is:
The angular speed of the new system is .
The transfer of heat between the bottom surface of the beaker and water inside it is due to Convection phenomenon. When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. ... The fluid above a hot surface expands, becomes less dense, and rises
Answer:
Average speed of Elain = 60 km/h
Explanation:
Total Distance covered by Jack = 360km
Average Speed of Jack = 80 km/h
Time taken by Jack to complete his journey = Distance / Average speed = 360 km / 80 km/h
Time taken by Jack to complete his journey = 4.5 hours
As it is given the both Jack and Elain travelled the same amount of distance:
Total distance travelled by Elain = 360 km
It is given that Elain took 1.5 hourse more than Jack to cover the distance, so Time taken by Elain to cover the distance is = 4.5 hours + 1.5 hours = 6 hours
Average speed of Elain = Distance/ time = 360 km / 6 hours
Average speed of Elain = 60 km/h
D = distance between the cars at the start of time = 680 km
v₁ = speed of one car
v₂ = speed of other car = v₁ - 10
t = time taken to meet = 4 h
distance traveled by one car in time "t" + distance traveled by other car in time "t" = D
v₁ t + v₂ t = D
(v₁ + v₂) t = D
inserting the values
(v₁ + v₁ - 10) (4) = 680
v₁ = 90 km/h
rate of slower car is given as
v₂ = v₁ - 10
v₂ = 90 - 10 = 80 km/h
