Scalar is a quantity such as mass or length that is completely determined by its own magnitude and has no direction. Therefore, your answer is Speed.
Answer:
2nd no. positive.... 3rd no. negitive......
Answer:
b) there must be a component of force parallel to the motion of the object.
Explanation:
We know that work done on a body by an external force is calculated by the formula given below:
W = F.d = Fd Cos θ
where,
W = Work Done by the force on the body
F = Magnitude of force
d = displacement of the body
θ = The angle between the direction of motion of the body and the force applied
It is clear from the formula of the work done, that "F Cosθ" represents the component of the force, that is acting in the direction of motion of the object or parallel to the direction of motion of the object. So, if there is no component of force parallel to motion of object, then this factor will become zero. As a result, the work done will also be zero.
Therefore, the correct option will be:
b) <u>there must be a component of force parallel to the motion of object.</u>
Answer:
(C) Watt
Explanation:
The unity of power is watt
Power is nothing but the rate of change of energy with respect to time
So power is given by 
, here W is work done and t is time
We know that unit of work done is joule and unit of time is sec
So unit of power is J/sec which is called watt
So option (c) will be correct option
