Answer:
Being a plane mirror the Image is formed 3 metres beyond the mirror . So total distance is 3+3 = 6metres
The sum of all forces applied to the object = (mass) x (acceleration)
The sum of all forces applied to the object = (30) x (15)
= <u>450 newtons</u>, in the direction of the acceleration.
Answer:

Explanation:
Let's use projectile motion equations. First of all we need to find the travel time. So we are going to use the next equation:
(1)
Where:






In this case:

Because the dog jumps horizontally
Let's asume the gravity constant as:


Because when the dog reach the base the height is 0


Now let's replace the data in (1)

Isolating t:

Finally let's find the horizontal displacement using this equation:

Replacing the data:

Answer:
The value of current through the rod becomes half

Explanation:
As per Ohm's law we know that the current through a resistor is given as

here we know that

here we know that the length of the cylinder is L and area is A so the value of current through the rod is given as

now we have change the length of the conductor to twice of initial value and rest all parameters will remain the same
so we will have

now from above two equations we have

so new current will become
