Advertisements
Advertisements
Question
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
Advertisements
Solution
Force applied by the car, (F) = 2.5 × 1010 N
Speed of the car, (v) = 5 m/s
Time taken, (t) = 120 s
So distance travelled,
Distance = Speed × Time
= 5 × 120 m
= 600 m
So, Work done = (Force) × (Distance)
= `2.5 xx 10^10 xx 600` J
= `1.5 xx 10^13` J
APPEARS IN
RELATED QUESTIONS
Work done = Force × ........................................
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
A force of 50 N acts on a body and moves it a distance of 4 m on horizontal surface. Calculate the work done if the direction of force is at an angle of 60° to the horizontal surface.
Determine the amount of work done when an object is displaced at an angle of 30° with respect to the direction of the applied force.
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
Is the motion of moon around the earth in circular path an accelerated motion?
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
One labourer carried four pans of road metal through a distance of 100 metres. If he carries two pans of road metal through a 200 metre distance ______ work will be done.
