Answer:
1,3
Explanation:
As the acceleration is -10m/s^2 , that means deceleration is occurring. That means, the object is slowing down.
v=u-at
or, 0=80-10t
or, t=8 seconds
So, the object will stop in 8 seconds.
So, the correct answers are 1 and 3.
Hope, this helps you.
If we want the object to continue to move at constant speed, it means that the resultant of the forces acting on the object must be zero. So far, we have:
- force F1 with direction north, of 10 N
- force F2 with direction west, of 10 N
The third force must balance them, in order to have a net force of zero on the object.
The resultant of the two forces F1 and F2 is

with direction at

north-west. This means that F3 must be equal and opposite to this force: so, F3 must have magnitude 14.1 N and its direction should be

south-east.
Answer:

Explanation:
It is given that,
Depth of Death valley is 85 m below sea level, 
The summit of nearby Mt. Whitney has an elevation of 4420 m, 
Mass of the hiker, m = 65 kg
We need to find the change in potential energy. It is given by :



or

So, the change in potential energy of the hiker is
. Hence, this is the required solution.
Answer:
Fission is the opposite of fusion and releases energy only when heavy nuclei are split. As noted in Fusion, energy is released if the products of a nuclear reaction have a greater binding energy per nucleon than the parent nuclei.
The amount of energy released during nuclear fission is millions of times more efficient per mass than that of coal considering only 0.1 percent of the original nuclei is converted to energy. Daughter nucleus, energy, and particles such as neutrons are released as a result of the reaction