<u>Answer:</u>
2.39 kg
<u>Explanation:</u>
There is conservation of momentum here in this problem so we will use the following problem:
where the mass of the student 
is 48.5 kg,
the mass of the skateboard 
is kg,
the initial speed of the student 
is 4.25 m/s; and
the speed of the student and skateboard 
is 4.05 m/s.
So substituting the given values in the above formula to get:
Therefore, the mass of the skateboard is 2.39 kg.
Answer:
differences and similarities
Explanation:
An electric bell is a mechanical or electronic bell that functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing, clanging or ringing sound. whereas,
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected.
<span>Cell membranes are selectively permeable because it allows some things to enter or leave the cell while keeping other things outside or inside the cell.</span>
Answer:
The value is 
and
Explanation:
From the question we are told that
The image distance is 
The focal length is 
From the lens equation we have that
=> 
=> 
Generally the magnification is
=> 
=>
Answer:
Efficiency can be increase by using rollers in conjunction with the inclined plane. Wedge. The wedge is an adaptation of the inclined plane. It can be used to raise a heavy load over a short distance or to split a log
