Respuesta :
Answer:
[tex]4.2\times10^3 W[/tex]
[tex]2.67\times 10^4 W[/tex]
Explanation:
Given:
Mass of the rider plus the bike, [tex]m=2\times10^2 kg[/tex]
Speed of the motorbike, u= 20 m/s
Force of resistance, [tex]F=2.1\times10^2N[/tex]
Power necessary to sustain speed can be calculated as follows:
1. When road is level
Power = force x velocity
P= F x u
[tex]P=(2.1\times10^2N)(20 m/s) = 4.2\times10^3 W[/tex]
2. When the road is sloped at an angle 35°
An additional force will act due to component of gravity that is
[tex]= mg sin \theta[/tex]
So,
[tex]P = (F+mgsin\theta)u\\ P= (2.1\times10^2+2\times10^2\times 9.8 \times sin35^o)(20)=2.67\times 10^4 W[/tex]
a. The power at which the road is level should be [tex]4.2 \times 10^3 W[/tex]
b. The power at which road is sloped upward should be [tex]2.67 \times 10^4W[/tex]
Calculation of the power is:
We know that
a. The power is the product of force and velocity
So,
[tex]= (2.1 \times 10^2 kg) (20 m/s)\\\\= 4.2 \times 10^3 W[/tex]
b. Now the power should be
[tex]= (2.1 \times 10^2 + 2 \times 10^2 \times 9.8 \times sin 35^{\circ}) (20)\\\\= 2.67 \times 10^4W[/tex]
Learn more about the speed here: https://brainly.com/question/14312961
