Answer:
36.87 km/h
Explanation:
Convert all the units in SI system
1 mile = 1609.34 m
d1 = 6 mi = 9656.04 m
t1 = 15 min = 15 x 60 = 900 s
d2 = 3 mi = 4828.02 m
t2 = 10 min = 10 x 60 = 600 s
d3 = 1 mi = 1609.34 m
t3 = 2 min = 2 x 60 = 120 s
d4 = 0.5 mi = 804.67 m
t4 = 0.5 min = 0.5 x 60 = 30 s
Total distance, d = d1 + d2 + d3 + d4
d = 9656.04 + 4828.02 + 1609.34 + 804.67 = 16898.07 m = 16.898 km
total time, t = t1 + t2 + t3 + t4
t = 900 + 600 + 120 + 30 = 1650 s = 0.4583 h
The ratio of the total distance covered to the total time taken is called average speed.
Average speed = 16.898 / 0.4583 = 36.87 km/h
After 20 s, the motorcycle attains a speed of

and it continues at this speed for the next 40 s. So at 45 s, its speed is 80 m/s.
Answer:
This is because when the pedal sprocket arms are in the horizontal position, it is perpendicular to the applied force, and the angle between the applied force and the pedal sprocket arms is 90⁰.
Also, when the pedal sprocket arms are in the vertical position, it is parallel to the applied force, and the angle between the applied force and the pedal sprocket arms is 0⁰.
Explanation:
τ = r×F×sinθ
where;
τ is the torque produced
r is the radius of the pedal sprocket arms
F is the applied force
θ is the angle between the applied force and the pedal sprocket arms
Maximum torque depends on the value of θ,
when the pedal sprocket arms are in the horizontal position, it is perpendicular to the applied force, and the angle between the applied force and the pedal sprocket arms is 90⁰.
τ = r×F×sin90⁰ = τ = r×F(1) = Fr (maximum value of torque)
Also, when the pedal sprocket arms are in the vertical position, it is parallel to the applied force, and the angle between the applied force and the pedal sprocket arms is 0⁰.
τ = r×F×sin0⁰ = τ = r×F(0) = 0 (torque is zero).
<span>Newton and Leibniz feuded over who invented calculus. Newton had proabaly come up with the idea eariler, but Leibniz took the spotlight by publishing first. Complicating things were their respecitve home countries, England and France, which had their own rivalry at the time. Further complicating matters was that they discovered different types of calculus, and had different notations. Today, beggining calculus students use methods and notations similar to Leibniz, but Newton's methods come into use in higher level classes.</span>