According to Newton, an object will only accelerate if there is a net or unbalanced forceacting upon it. The presence of an unbalanced force will accelerate an object - changing its speed, its direction, or both its speed and direction.
Answer:
a) 14.2sec
b) 1394m away if horizontal speed never changes
c) 9.8m/s
Explanation:
Answer:
It is neither false nor true. When they collide some of one of the objects goes to the other object.
Explanation:
Answer:
a) 
b) 

Explanation:
Searching the missed information we have:
E: is the energy emitted in the plutonium decay = 8.40x10⁻¹³ J
m(⁴He): is the mass of the helium nucleus = 6.68x10⁻²⁷ kg
m(²³⁵U): is the mass of the helium U-235 nucleus = 3.92x10⁻²⁵ kg
a) We can find the velocities of the two nuclei by conservation of linear momentum and kinetic energy:
Linear momentum:


Since the plutonium nucleus is originally at rest,
:
(1)
Kinetic Energy:

(2)
By entering equation (1) into (2) we have:
Solving the above equation for
we have:

And by entering that value into equation (1):
The minus sign means that the helium-4 nucleus is moving in the opposite direction to the uranium-235 nucleus.
b) Now, the kinetic energy of each nucleus is:
For He-4:

For U-235:

I hope it helps you!