Given:
m(mass of the box)=10 Kg
t(time of impact)=4 sec
u(initial velocity)=0.(as the body is initially at rest).
v(final velocity)=25m/s
Now we know that
v=u+at
Where v is the final velocity
u is the initial velocity
a is the acceleration acting on the body
t is the time of impact
Substituting these values we get
25=0+a x 4
4a=25
a=6.25m/s^2
Now we also know that
F=mxa
F=10 x6.25
F=62.5N
Answer:
h=15.27m
Explanation:
Since at maximum height the vertical velocity must be null it's better to use the formula:

We will use this formula for the vertical direction, choosing the upward direction as the positive one, so we have:

or

which for our values is:

Answer:
350 N/m
Explanation:
If we are assuming the stretch does not exceed the elastic range of the material, then by Hooke's law the spring constant of the cord is simply the ratio between the force 70N acting on the cord to stretch 20cm or 0.2m
k = 70 / 0.2 = 350 N/m
The spring constant is 350 N/m
Answer:
the answer is B
Explanation:
speed is the rate at which the distance covered changes or the distance divided by the time taken.
scalar is always positive.
Answer:
Newton
Explanation:
The earth attracts every body towards its centre. The force with which the earth attracts any body towards its centre, is called its weight.
It is a vector quantity.
It always acts towards the centre of earth.
The SI unit of Newton.