Answer:
To have a positive job, the two vectors must have the same direction
Explanation:
Work is a scalar defined as the scalar product of two vectors, the froce and the displacement. To have a positive job, the two vectors must have
collinear and that their arrows point in the same direction.
You can also appreciate this from the work equation
W = F. r
bold indicate vector
W = F r cos θ
With θ the angle between force and displacement
The force acting in the front direction is the 130N.
The frictional force is acting backwards 30N.
1) The net force is 130N - 30N = 100N
2) s = ut + (1/2)at^2 u = 0, Start from rest, s = 25m t =5.
25 = 0*5 + (1/2)* a * 5^2.
25 = 0 + 25/2 * a.
25 = (25/2)a. Divide 25 from both sides.
1 = (1/2)* a. Cross multiply.
2 = a.
a = 2 m/s^2.
3) Mass of the box
Net Force, F = ma
100 = m*2. Divide both sides by 2.
100/2 = m
50 = m.
m = 50 kg.
4) Final velocity , v = u + at.
v = 0 + 2*5 = 10 m/s.
Kinetic Energy, K = (1/2) * mv^2.
= 1/2 * 50 * 10 * 10.
= 2500 J.
Answer: option C.
Fabrics such as cotton and silk are synthetic polymers
Explanation:
Fabrics such as cotton and silk are synthetic polymers because cotton and silk are natural polymers meaning they are gotten from natural source. Cotton is gotten from cotton plants and it is composed of cellulose which is a carbohydrates.
Silk also is gotten from animals I.efrom insect fibre or the cocoons of the larvae of the mulberry silkworm which is a polymer.
Ocean currents are formed by a type of heat transfer that is convection
Answer:
W = 8.01 × 10^(-17) [J]
Explanation:
To solve this problem we need to know the electron is a subatomic particle with a negative elementary electrical charge (-1,602 × 10-19 C), The expression to calculate the work is given by:
W = q*V
where:
q = charge = 1,602 × 10^(-19) [C]
V = voltage = 500 [V]
W = work [J]
W = 1,602 × 10^(-19) * 500
W = 8.01 × 10^(-17) [J]
