The mass of the skateboard is 1.8kg and the mass of the skateboarder is 42kg. calculate the velocity at which the skateboard moves backwards if the skateboarder jumps forward at a velocity of 0.3m/s. asap ; -;

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Calculate the first and second velocities of the car with four washers attached to the pulley, using the formulas v1 = 0.25 m / t1 , and v2 = 0.25 m / (t2 – t1) where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. record these velocities, to two decimal places, in table e.

Ablock of mass m slides on a horizontal frictionless table with an initial speed v0 . it then compresses a spring of force constant k and is brought to rest. the acceleration of gravity is 9.8 m/s2 . how much is the spring compressed x from its natural length?