Answer:
time is 3333.33 min or 55.55 hr
Explanation:
given data
reactor operating = 1 MW
negative reactivity = $5
power = 1 miliwatt
to find out
how long does it take
solution
we know here power coefficient that is
power coefficient = 
power coefficient = 1
so time required to reach power is
power = reactivity × time / power coefficient + reactor operating
1 ×
= -5 t / 1 + 1 × 
5t =
- 
t = 199999.99 sec
so time is 3333.33 min or 55.55 hr
Answer:

Explanation:
given,
weight of swimmer = 510 N
length of ledge, L = 1.75 m
vertical height of the cliff, h = 9 m
speed of the swimmer = ?
horizontal velocity of the swimmer should be that much it can cross the wedge.
distance = speed x time
d = v_x × t
1.75 = v_x × t ........(1)
now,time taken by the swimmer to cover 9 m
initial vertical velocity of the swimmer is zero.
using equation of motion for time calculation


t² = 1.938
t = 1.39 s
same time will be taken to cover horizontal distance.
now, from equation 1
1.75 = v_x × 1.39

horizontal speed of the swimmer is equal to 1.26 m/s
3, protons are positive and there are 3 positive atoms visible
Answer:
The frictional force needed to overcome the cart is 4.83N
Explanation:
The frictional force can be obtained using the following formula:

where
is the coefficient of friction = 0.02
R = Normal reaction of the load =
=
= 
Now that we have the necessary parameters that we can place into the equation, we can now go ahead and make our substitutions, to get the value of F.

F = 4.83 N
Hence, the frictional force needed to overcome the cart is 4.83N