Question by klh.™ – he’s here 3.14.10: Physical Science Physics Questions?
1. Calculate the distance a plane flies on a 7.95-hour flight from Chicago to London. Assume a constant speed of 800.0 km/h.
2. Determine a skier’s velocity in kilometers per hour if it takes her 1.7 minutes to ski down a 1.67 km slope.
3. Calculate the average acceleration of a car that changes speed from 0 m/s to 15 m/s in 5 s.
4. Calculate how long it takes for a stone falling from a bridge with an average acceleration downward of 9.8 m/s2 to hit the water. The stone starts from rest and hits the water with a velocity of 12.3 m/s.
5. Identify the straight-line accelerations below as either speeding up or slowing down.
a. 0.75 m/s2
b. 24.8 m/s2
Answer by Poh
1. Distance = average speed x time taken
2. Velocity = distance / time
3. Acceleration = change in velocity / time taken
4. Using formula v = u + at, where v is final velocity, u is initial velocity, a is acceleration and t is time.
Re arranging gives, t = (v – u)/a and “u = 0″ since it starts from rest.
5. A negative acceleration means it’s slowing down.
What do you think? Answer below!