#average speed

Question: A car travels the first half of a distance between two places at a speed of 30 Kmh-1 and the second half of the distance at 50 Kmh-1.What is the average speed of the car for the whole journey? Solution: Average speed of the car: Average speed of a car ALITER: Average speed of the car $${=\frac{2v_1v_2}{v_1+v_2}}$$ Speed of the car at the first half distance (v1)= 30Kmh-1 Speed…

Question: A particle covers 3/4 th of total distance with speed v1 and next 1/4 th with speed v2. Find the average speed of the particle. Solution: $$Average \ speed = \frac{Total \ distance}{Total \ time \ taken}$$ Total distance is $${\frac{3}{4}(d)+\frac {1}{4}(d) =d}$$ Let the speed be v1 for the 3/4 th distance and v2 for the next 1/4 th distance. Time taken to cover 3/4 th distance…

Question: A car covers the first half of the distance between two places at a speed 40 Kmh-1 and the second half at 60 Kmh-1.What is the average speed of the car? Solution: $${Average \ speed = \frac{Total \ distance} {Total \ time \ taken}}$$ Let the distance between the two places be ‘2d’ Km Time taken by the car to cover the first half of the journey $${time =\frac{distance}{speed}=\frac…

I don’t ride fast enough to need a faster bike. You know: a newer bike, a lighter bike, a bike with 12 cogs in the back, a bike with a carbon-fiber frame. My average speed this year has been somewhere around 12.5 miles per hour. Tandem ride? 12.5 mph. Tricycle ride? 12.5 mph. Fixed-gear bike? Well, this morning, just over 13 mph. But usually? 12.5 mph. Riding with a frame bag? 12.5 mph. Seat…

Madagascar: Batsirai touches the ground, now weaker

(ANSA) – VATOMANDRY, 06 FEB – Cyclone Batsirai, which arrived on Madagascar last night with winds up to a maximum speed of 165 km per hour, is gradually weakening but floods are still expected in the east of the country due to persistent heavy rains. The national meteorological office fears “extensive and widespread damage” caused by the disturbance, which had alerted millions of people and…

Do Electric Cars Need 600 Miles Of Range? Well, No They Don't. 

The Starship Enterprise returns from warp drive to ordinary space with a forward speed of 51 km/s. To the crew's great surprise, a Klingon ship is 150 km directly ahead, traveling in the same direction at a mere 21 km/s. Without evasive action, the Enterprise will overtake and collide with the Klingons in just about 5.0 s. The Enterprise's computers react instantly to brake the ship. PART A. What magnitude acceleration does the Enterprise need to just barely avoid a collision with the Klingon ship? Assume the acceleration is constant.

The Starship Enterprise returns from warp drive to ordinary space with a forward speed of 51 km/s. To the crew’s great surprise, a Klingon ship is 150 km directly ahead, traveling in the same direction at a mere 21 km/s. Without evasive action, the Enterprise will overtake and collide with the Klingons in just about 5.0 s. The Enterprise’s computers react instantly to brake the ship. PART A. What…

A particle's velocity is described by the function vx=kt2, where vx is in m/s, t is in s, and k is a constant. The particle's position at t0=0s is x0 = -7.90 m . At t1 = 1.00 s , the particle is at x1 = 8.70 m .

A particle’s velocity is described by the function where is in m/s, t is in s, and k is a constant. The particle’s position at is . At , the particle is at . PART A. Determine the units of k in terms of m and s.

ANSWER:

We know that the unit for velocity is m/s and the unit for time is s. Therefore,

PART B. Determine the value of the constant k.

ANSWER:

Solve for C using the pairs