Mass number = no. of protons + no. of neutrons
so, it would be, 3+4 = 7
Answer:

Explanation:
Net force by which man push the lawn mower is given as

now it is given that 37% of this force is vertically downwards
so we will have


now we also know that

here we have


Now work done by this force to move the lawn mower is given as



Answer:
A. The volume of the object
Explanation:
First of all, it can only PROBABLY be A or D
But why is it only A?
- Mass = The amount of matter in an object (nothing related here)
- Volume = How much space is the object taking (super related here)
It's VOLUME here and not MASS here because:
- It it would be Mass, then the object size could be anything, but the liquid wouldn't move as much higher.
- But because it is Volume, it is taking space, which makes the liquid move
- If the Mass would be the answer, then it would be totally not related, because mass isn't related over here, it matters about size.
<h2>
Hence, A. The volume of the object </h2>
is your answer!!!!
Answer:
The kinetic energy of the particle will be 12U₀
Explanation:
Given that,
A particle is launched from point B with an initial velocity and reaches point A having gained U₀ joules of kinetic energy.
Constant force = 12F
According to question,
The kinetic energy is
....(I)
Constant force = 12F
A resistive force field is now set up ,
Resistive force is given by,

When the particle moves from point B to point A then,
We need to calculate the kinetic energy
Using formula for kinetic energy

Put the value of 

Now, from equation (I)

Hence, The kinetic energy of the particle will be 12U₀.