The correct answer is (a.) The rider uses energy to do work going up the mountain. As the law of conservation of energy states that the total energy must be constant, therefore, the energy that is used to go up will be as it is to go down.
Answer:
30m/s
Explanation:
From law of motion equation
Vf= Vi + at
Where Vf= final velocity
Vi= initial velocity=0(the car started at rest)
a= acceleration= 3m/s2
t= time= 10s
Then substitute into the equation to get the final velocity.
Vf= 0+(10×3)
Vf= 30m/s
Hence, the car's final velocity is 30m/s
Let's use ' t ' to represent half of the time, in hours.
The distance traveled in the first half of the time is (80 t) km.
The distance traveled in the last half of the time is (40 t) km.
The total distance covered is (80t + 40t) = (120t) km.
You said that the total distance covered was 60 km,
so ...
120 t = 60 km
Divide each side by 120 : t (half of the time) = 0.5 hour
Average speed = (total distance covered) / (time to cover the distance)
= (60 km) / (1 hour)
= 60 km/hr .
Answer:
The acceleration motorcycle
a = 5.13 m / s²
Explanation:
Now to determine the acceleration of the motorcycle
Use the force to analysis motion
∑ F = m * a
∑ F = E - D - m*g * sin ( β ) = m * a
E = 3168 N
D = 230 N
β = 31.6 °
3168 N - 230 N - 286 kg * 9.8 m / s² * sin ( 31.6° ) = 286 kg * a
Now solve to a'
a = [ 3168 N - 230 N - 286 kg * 9.8 m / s² * sin ( 31.6° ) ] / (286 kg)
a = 5.13 m / s²
Answer:
Torque = –207.4 Nm
Explanation:
Given M = 3.2kg, r = 5.4m, α = –12rad/s² (it is slowing down)
Torque = I × α
α = angular acceleration
I = moment of inertia
I = MR² for a circular hoop
Torque = 3.2×5.4×(– 12)
Torque = –207.4 Nm