Answer:
9 m/s
Explanation:
mass of cannon, M = 100 kg
mass of cannon ball, m = 10 kg
velocity of cannon ball, v = 90 m/s
Let the recoil velocity of cannon is V.
Us ethe conservation of linear momentum, as no external force is acting on the system, so the linear momentum of the system is conserved.
Momentum before the firing = momentum after the firing
M x 0 + m x 0 = M x V + m x v
0 = 100 x V + 10 x 90
V = - 9 m/s
Thus, the recoil velocity of cannon is 9 m/s.
Answer:
A:- 50 J
B:- 500 J
Explanation:
a) Given that a 25 N force is applied to move the box. Also the floor is having friction surface.
So in order to move the box, the floor should have friction of atleast 25 N.
∴ friction = 25 N
Work done = force * displacement of box
Given, the box is moved 2 m across the floor
So, Work done = friction * 2 m
= 25 * 2
= 50 J
b) Given, the box is having weight of 250 N weight
Gravitational force is acting on the box which is equal to (mass * gravity)
∴ Force = 250 N
The box is lifted 2 m above the floor.
So, displacement = 2 m
Work done = force * displacement of box
Work done = 250 * 2
= 500 J
B they belong to the same family of elements
<u>Answer:</u>
At time 2t the paint ball is at 8 cm to the right and 16 cm to the bottom
<u>Explanation:</u>
We have equation of motion ,
, s is the displacement, u is the initial velocity, a is the acceleration and t is the time.
Considering the horizontal motion of paint ball
Distance traveled during time t = 4 cm
Initial velocity = u m/s
Acceleration = 0 
So 
Now at time 2t,

So horizontal distance traveled in time 2t = 8 cm to the right
Now considering the vertical motion of paint ball
Distance traveled during time t = 4 cm
Initial velocity = 0 m/s
Acceleration = -g 

At time 2t,

So vertical distance traveled in time 2t = 16 cm to the bottom
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3000 to 1200 BCE.