Answer:
<em>The distance is now 4d</em>
Explanation:
<u>Mechanical Force</u>
According to the second Newton's law, the net force exerted by an external agent on an object of mass m is:
F = m.a
Where a is the acceleration of the object.
The acceleration can be calculated by solving for a:

Once we know the acceleration, we can calculate the distance traveled by the block as follows:

If the block starts from rest, vo=0:

Substituting the value of the acceleration:

Simplifying:

When a force F'=4F is applied and assuming the mass is the same, the new acceleration is:

And the distance is now:

Dividing d'/d:

Simplifying:

Thus:
d' = 4d
The distance is now 4d
Answer:

Explanation:
Power is defined as the energy produced (E) per unit of time (t):

This means that the energy produced in the Sun each second (1 s), given the power
, is

Each p-p chain reaction produces an amount of energy of

in order to get the total number of p-p chain reactions per second, we need to divide the total energy produced per second by the energy produced by each reaction:

Car X traveled 3d distance in t time. Car Y traveled 2d distance in t time. Therefore, the speed of car X, is 3d/t, the speed of car Y, is 2d/t. Since speed is the distance taken in a given time.
In figure-2, they are at the same place, we are asked to find car Y's position when car X is at line-A. We can calculate the time car X needs to travel to there. Let's say that car X reaches line-A in t' time.

Okay, it takes t time for car X to reach line-A. Let's see how far does car Y goes.

We found that car Y travels 2d distance. So, when car X reaches line-A, car Y is just a d distance behind car X.
Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .