Thursday

July 31, 2014

July 31, 2014

Total # Posts: 6

**physics**

An open railroad car of mass 2449 kg is coasting with an initial speed of 17 m/s on a frictionless, horizontal track. It is raining, and water begins to accumulate in the car. After some time, it is found that the speed of the car is only 10 m/s. How much water (in kilograms) ...

**physics**

A railroad car containing explosive material is initially traveling south at a speed of 4.5 m/s on level ground. The total mass of the car plus explosives is 2.9 104 kg. An accidental spark ignites the explosive, and the car breaks into two pieces, which then roll away along t...

**physics**

Two objects of mass m1 = m and m2 = 4m undergo a completely inelastic collision in one dimension. If the two objects are at rest after the collision, what was the ratio of their speeds before the collision? v1/v2=

**physics**

A rubber ball (mass 0.21 kg) is dropped from a height of 1.7 m onto the floor. Just after bouncing from the floor, the ball has a speed of 3.6 m/s. (a) What is the magnitude and direction of the impulse imparted by the floor to the ball? Magnitude? Direction? (b) If the averag...

**physic**

A hockey player strikes a puck that is initially at rest. The force exerted by the stick on the puck is 950 N, and the stick is in contact with the puck for 4.4 ms (0.0044 s). (a) Find the impulse imparted by the stick to the puck. (b) What is the speed of the puck (m = 1.70 k...

**physics**

Consider two cars, one a compact model (m = 781 kg) and the other an SUV (m = 2483 kg). The SUV is traveling at 15 m/s, while the compact car is traveling at an unknown speed v. If the two cars have the same momentum, what is v?

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