A block sliding across the floor slows at a rate of −1.5 m/s2. It takes the block 2.0 seconds to stop over a distance of 3.0 meters. Calculate its initial speed.

A car starts from rest at t = 0 s, and speeds up with a constant acceleration of 1.81 m/s2 for 6.00 s. Then it continues with a uniform speed for another 6.00 s. Finally, it speeds up with a constant acceleration of 2.02 m/s2 until it reaches a speed of 18.0 m/s. (a) Draw the velocity vs. time and acceleration vs. time graphs for this motion. Numerical values on the graphs are not required. (b) How long does it take for the car to reach a speed of 18.0 m/s? Time is measured from the beginning at t = 0 s (c) What is the total displacement of the car?

A Thomson's gazelle can run at very high speeds, but its acceleration is relatively modest. A reasonable model for the sprint of a gazelle assumes an acceleration of 4.2 m/s2m/s2 for 6.5 ss , after which the gazelle continues at a steady speed. What is the gazelle's top speed? Express your answer with the appropriate units.   A human would win a very short race with a gazelle. The best time for a 30 mm sprint for a human runner is 3.6 ss. How much time would the gazelle take for a 30 mm race? Express your answer with the appropriate units.   A gazelle would win a longer race. The best time for a 200 mm sprint for a human runner is 19.3 ss. How much time would the gazelle take for a 200 mm race? Express your answer with the appropriate units.

A brick is dropped from the roof of a tall building. After it has been falling for a few seconds, it falls 41.0 mm in a 1.00-ss time interval.What distance will it fall during the next 1.00 s? Ignore air resistance.

A rocket, initially at rest on the ground, accelerates straight upward from rest with constant acceleration 44.1m/s2 . The acceleration period lasts for time 5.00s until the fuel is exhausted. After that, the rocket is in free fall.Find the maximum height ymax reached by the rocket. Ignore air resistance and assume a constant acceleration due to gravity equal to 9.80 m/s2 . Write your answer numerically in units of meters.

A car starts from rest at t = 0 s, and speeds up with a constant acceleration of 1.81 m/s2 for 6.00 s. Then it continues with a uniform speed for another 6.00 s. Finally, it speeds up with a constant acceleration of 2.02 m/s2 until it reaches a speed of 18.0 m/s. (a) How long does it take for the car to reach a speed of 18.0 m/s? Time is measured from the beginning at t = 0  (b) What is the total displacement of the car?

A subway train starts from rest at a station and accelerates at a rate of 1.60 m/s2 for 14.0 s. It runs at constant speed for 70.0 seconds and slows down at a rate of 3.50 m/s2 until it stops at the next station. Find the total distance covered.

A rocket, initially at rest on the ground, accelerates upward with a constant acceleration of 94.0 m/s2 until it reaches a speed of 1.50E2 m/s when the engines are cut off. After that, the rocket is in free-fall. What is the maximum height reached by the rocket?

A plane accelerates from rest at a constant rate of 5.20 m/s2 along a runway that is 1900 m long. Assume that the plane reaches the required takeoff velocity at the end of the runway. What is the time t needed to take off?

A runner of mass 50.1 kg stařts from rest and accelerates with a constant acceleration of 1.1 m/s2 until she reaches a velocity of 6.5 m/s. She then continues running at this constant velocity. How long in seconds does the runner take to travel 104 m? 载